ent/doc: o2m two types example

Reviewed By: idoshveki

Differential Revision: D17050002

fbshipit-source-id: 183c41bfb8cffb463a80a80590a01aba176e3b2a

examples/o2m2types/README.md

@@ -0,0 +1,12 @@
+# User-Pets O2M Relation
+
+An example for a O2M (one-to-many) relation between a user and its pets.  
+Each user **has many** pets, and a pet **has one** owner. If a user A adds
+a pet B using the pets edge, B can get its owner using the owner edge.
+
+
+### Generate Assets
+
+```console
+go generate ./...
+```

examples/o2m2types/ent/client.go

@@ -0,0 +1,179 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+	"fmt"
+	"log"
+
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/migrate"
+
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/pet"
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/user"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// Client is the client that holds all ent builders.
+type Client struct {
+	config
+	// Schema is the client for creating, migrating and dropping schema.
+	Schema *migrate.Schema
+	// Pet is the client for interacting with the Pet builders.
+	Pet *PetClient
+	// User is the client for interacting with the User builders.
+	User *UserClient
+}
+
+// NewClient creates a new client configured with the given options.
+func NewClient(opts ...Option) *Client {
+	c := config{log: log.Println}
+	c.options(opts...)
+	return &Client{
+		config: c,
+		Schema: migrate.NewSchema(c.driver),
+		Pet:    NewPetClient(c),
+		User:   NewUserClient(c),
+	}
+}
+
+// Tx returns a new transactional client.
+func (c *Client) Tx(ctx context.Context) (*Tx, error) {
+	if _, ok := c.driver.(*txDriver); ok {
+		return nil, fmt.Errorf("ent: cannot start a transaction within a transaction")
+	}
+	tx, err := newTx(ctx, c.driver)
+	if err != nil {
+		return nil, fmt.Errorf("ent: starting a transaction: %v", err)
+	}
+	cfg := config{driver: tx, log: c.log, verbose: c.verbose}
+	return &Tx{
+		config: cfg,
+		Pet:    NewPetClient(cfg),
+		User:   NewUserClient(cfg),
+	}, nil
+}
+
+// PetClient is a client for the Pet schema.
+type PetClient struct {
+	config
+}
+
+// NewPetClient returns a client for the Pet from the given config.
+func NewPetClient(c config) *PetClient {
+	return &PetClient{config: c}
+}
+
+// Create returns a create builder for Pet.
+func (c *PetClient) Create() *PetCreate {
+	return &PetCreate{config: c.config}
+}
+
+// Update returns an update builder for Pet.
+func (c *PetClient) Update() *PetUpdate {
+	return &PetUpdate{config: c.config}
+}
+
+// UpdateOne returns an update builder for the given entity.
+func (c *PetClient) UpdateOne(pe *Pet) *PetUpdateOne {
+	return c.UpdateOneID(pe.ID)
+}
+
+// UpdateOneID returns an update builder for the given id.
+func (c *PetClient) UpdateOneID(id int) *PetUpdateOne {
+	return &PetUpdateOne{config: c.config, id: id}
+}
+
+// Delete returns a delete builder for Pet.
+func (c *PetClient) Delete() *PetDelete {
+	return &PetDelete{config: c.config}
+}
+
+// DeleteOne returns a delete builder for the given entity.
+func (c *PetClient) DeleteOne(pe *Pet) *PetDeleteOne {
+	return c.DeleteOneID(pe.ID)
+}
+
+// DeleteOneID returns a delete builder for the given id.
+func (c *PetClient) DeleteOneID(id int) *PetDeleteOne {
+	return &PetDeleteOne{c.Delete().Where(pet.ID(id))}
+}
+
+// Create returns a query builder for Pet.
+func (c *PetClient) Query() *PetQuery {
+	return &PetQuery{config: c.config}
+}
+
+// QueryOwner queries the owner edge of a Pet.
+func (c *PetClient) QueryOwner(pe *Pet) *UserQuery {
+	query := &UserQuery{config: c.config}
+	id := pe.ID
+	t1 := sql.Table(user.Table)
+	t2 := sql.Select(pet.OwnerColumn).
+		From(sql.Table(pet.OwnerTable)).
+		Where(sql.EQ(pet.FieldID, id))
+	query.sql = sql.Select().From(t1).Join(t2).On(t1.C(user.FieldID), t2.C(pet.OwnerColumn))
+
+	return query
+}
+
+// UserClient is a client for the User schema.
+type UserClient struct {
+	config
+}
+
+// NewUserClient returns a client for the User from the given config.
+func NewUserClient(c config) *UserClient {
+	return &UserClient{config: c}
+}
+
+// Create returns a create builder for User.
+func (c *UserClient) Create() *UserCreate {
+	return &UserCreate{config: c.config}
+}
+
+// Update returns an update builder for User.
+func (c *UserClient) Update() *UserUpdate {
+	return &UserUpdate{config: c.config}
+}
+
+// UpdateOne returns an update builder for the given entity.
+func (c *UserClient) UpdateOne(u *User) *UserUpdateOne {
+	return c.UpdateOneID(u.ID)
+}
+
+// UpdateOneID returns an update builder for the given id.
+func (c *UserClient) UpdateOneID(id int) *UserUpdateOne {
+	return &UserUpdateOne{config: c.config, id: id}
+}
+
+// Delete returns a delete builder for User.
+func (c *UserClient) Delete() *UserDelete {
+	return &UserDelete{config: c.config}
+}
+
+// DeleteOne returns a delete builder for the given entity.
+func (c *UserClient) DeleteOne(u *User) *UserDeleteOne {
+	return c.DeleteOneID(u.ID)
+}
+
+// DeleteOneID returns a delete builder for the given id.
+func (c *UserClient) DeleteOneID(id int) *UserDeleteOne {
+	return &UserDeleteOne{c.Delete().Where(user.ID(id))}
+}
+
+// Create returns a query builder for User.
+func (c *UserClient) Query() *UserQuery {
+	return &UserQuery{config: c.config}
+}
+
+// QueryPets queries the pets edge of a User.
+func (c *UserClient) QueryPets(u *User) *PetQuery {
+	query := &PetQuery{config: c.config}
+	id := u.ID
+	query.sql = sql.Select().From(sql.Table(pet.Table)).
+		Where(sql.EQ(user.PetsColumn, id))
+
+	return query
+}

examples/o2m2types/ent/config.go

@@ -0,0 +1,51 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"github.com/facebookincubator/ent/dialect"
+)
+
+// Option function to configure the client.
+type Option func(*config)
+
+// Config is the configuration for the client and its builder.
+type config struct {
+	// driver is the driver used for execute database requests.
+	driver dialect.Driver
+	// verbose enable a verbosity logging.
+	verbose bool
+	// log used for logging on verbose mode.
+	log func(...interface{})
+}
+
+// Options applies the options on the config object.
+func (c *config) options(opts ...Option) {
+	for _, opt := range opts {
+		opt(c)
+	}
+	if c.verbose {
+		c.driver = dialect.Debug(c.driver, c.log)
+	}
+}
+
+// Verbose sets the client logging to verbose.
+func Verbose() Option {
+	return func(c *config) {
+		c.verbose = true
+	}
+}
+
+// Log sets the client logging to verbose.
+func Log(fn func(...interface{})) Option {
+	return func(c *config) {
+		c.log = fn
+	}
+}
+
+// Driver configures the client driver.
+func Driver(driver dialect.Driver) Option {
+	return func(c *config) {
+		c.driver = driver
+	}
+}

examples/o2m2types/ent/context.go

@@ -0,0 +1,20 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+)
+
+type contextKey struct{}
+
+// FromContext returns the Client stored in a context, or nil if there isn't one.
+func FromContext(ctx context.Context) *Client {
+	c, _ := ctx.Value(contextKey{}).(*Client)
+	return c
+}
+
+// NewContext returns a new context with the given Client attached.
+func NewContext(parent context.Context, c *Client) context.Context {
+	return context.WithValue(parent, contextKey{}, c)
+}

examples/o2m2types/ent/ent.go

@@ -0,0 +1,192 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/facebookincubator/ent/dialect"
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// Order applies an ordering on either graph traversal or sql selector.
+type Order func(*sql.Selector)
+
+// Asc applies the given fields in ASC order.
+func Asc(fields ...string) Order {
+	return Order(
+		func(s *sql.Selector) {
+			for _, f := range fields {
+				s.OrderBy(sql.Asc(f))
+			}
+		},
+	)
+}
+
+// Desc applies the given fields in DESC order.
+func Desc(fields ...string) Order {
+	return Order(
+		func(s *sql.Selector) {
+			for _, f := range fields {
+				s.OrderBy(sql.Desc(f))
+			}
+		},
+	)
+}
+
+// Aggregate applies an aggregation step on the group-by traversal/selector.
+type Aggregate struct {
+	// SQL the column wrapped with the aggregation function.
+	SQL func(*sql.Selector) string
+}
+
+// As is a pseudo aggregation function for renaming another other functions with custom names. For example:
+//
+//	GroupBy(field1, field2).
+//	Aggregate(ent.As(ent.Sum(field1), "sum_field1"), (ent.As(ent.Sum(field2), "sum_field2")).
+//	Scan(ctx, &v)
+//
+func As(fn Aggregate, end string) Aggregate {
+	return Aggregate{
+		SQL: func(s *sql.Selector) string {
+			return sql.As(fn.SQL(s), end)
+		},
+	}
+}
+
+// Count applies the "count" aggregation function on each group.
+func Count() Aggregate {
+	return Aggregate{
+		SQL: func(s *sql.Selector) string {
+			return sql.Count("*")
+		},
+	}
+}
+
+// Max applies the "max" aggregation function on the given field of each group.
+func Max(field string) Aggregate {
+	return Aggregate{
+		SQL: func(s *sql.Selector) string {
+			return sql.Max(s.C(field))
+		},
+	}
+}
+
+// Mean applies the "mean" aggregation function on the given field of each group.
+func Mean(field string) Aggregate {
+	return Aggregate{
+		SQL: func(s *sql.Selector) string {
+			return sql.Avg(s.C(field))
+		},
+	}
+}
+
+// Min applies the "min" aggregation function on the given field of each group.
+func Min(field string) Aggregate {
+	return Aggregate{
+		SQL: func(s *sql.Selector) string {
+			return sql.Min(s.C(field))
+		},
+	}
+}
+
+// Sum applies the "sum" aggregation function on the given field of each group.
+func Sum(field string) Aggregate {
+	return Aggregate{
+		SQL: func(s *sql.Selector) string {
+			return sql.Sum(s.C(field))
+		},
+	}
+}
+
+// ErrNotFound returns when trying to fetch a specific entity and it was not found in the database.
+type ErrNotFound struct {
+	label string
+}
+
+// Error implements the error interface.
+func (e *ErrNotFound) Error() string {
+	return fmt.Sprintf("ent: %s not found", e.label)
+}
+
+// IsNotFound returns a boolean indicating whether the error is a not found error.
+func IsNotFound(err error) bool {
+	_, ok := err.(*ErrNotFound)
+	return ok
+}
+
+// MaskNotFound masks nor found error.
+func MaskNotFound(err error) error {
+	if IsNotFound(err) {
+		return nil
+	}
+	return err
+}
+
+// ErrNotSingular returns when trying to fetch a singular entity and more then one was found in the database.
+type ErrNotSingular struct {
+	label string
+}
+
+// Error implements the error interface.
+func (e *ErrNotSingular) Error() string {
+	return fmt.Sprintf("ent: %s not singular", e.label)
+}
+
+// IsNotSingular returns a boolean indicating whether the error is a not singular error.
+func IsNotSingular(err error) bool {
+	_, ok := err.(*ErrNotSingular)
+	return ok
+}
+
+// ErrConstraintFailed returns when trying to create/update one or more entities and
+// one or more of their constraints failed. For example, violation of edge or field uniqueness.
+type ErrConstraintFailed struct {
+	msg  string
+	wrap error
+}
+
+// Error implements the error interface.
+func (e ErrConstraintFailed) Error() string {
+	return fmt.Sprintf("ent: unique constraint failed: %s", e.msg)
+}
+
+// Unwrap implements the errors.Wrapper interface.
+func (e *ErrConstraintFailed) Unwrap() error {
+	return e.wrap
+}
+
+// IsConstraintFailure returns a boolean indicating whether the error is a constraint failure.
+func IsConstraintFailure(err error) bool {
+	_, ok := err.(*ErrConstraintFailed)
+	return ok
+}
+
+func isSQLConstraintError(err error) (*ErrConstraintFailed, bool) {
+	// Error number 1062 is ER_DUP_ENTRY in mysql, and "UNIQUE constraint failed" is SQLite prefix.
+	if msg := err.Error(); strings.HasPrefix(msg, "Error 1062") || strings.HasPrefix(msg, "UNIQUE constraint failed") {
+		return &ErrConstraintFailed{msg, err}, true
+	}
+	return nil, false
+}
+
+// rollback calls to tx.Rollback and wraps the given error with the rollback error if occurred.
+func rollback(tx dialect.Tx, err error) error {
+	if rerr := tx.Rollback(); rerr != nil {
+		err = fmt.Errorf("%s: %v", err.Error(), rerr)
+	}
+	if err, ok := isSQLConstraintError(err); ok {
+		return err
+	}
+	return err
+}
+
+// keys returns the keys/ids from the edge map.
+func keys(m map[int]struct{}) []int {
+	s := make([]int, 0, len(m))
+	for id, _ := range m {
+		s = append(s, id)
+	}
+	return s
+}

examples/o2m2types/ent/example_test.go

@@ -0,0 +1,77 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+	"log"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// dsn for the database. In order to run the tests locally, run the following command:
+//
+//	 ENT_INTEGRATION_ENDPOINT="root:pass@tcp(localhost:3306)/test?parseTime=True" go test -v
+//
+var dsn string
+
+func ExamplePet() {
+	if dsn == "" {
+		return
+	}
+	ctx := context.Background()
+	drv, err := sql.Open("mysql", dsn)
+	if err != nil {
+		log.Fatalf("failed creating database client: %v", err)
+	}
+	defer drv.Close()
+	client := NewClient(Driver(drv))
+	// creating vertices for the pet's edges.
+
+	// create pet vertex with its edges.
+	pe := client.Pet.
+		Create().
+		SetName("string").
+		SaveX(ctx)
+	log.Println("pet created:", pe)
+
+	// query edges.
+
+	// Output:
+}
+func ExampleUser() {
+	if dsn == "" {
+		return
+	}
+	ctx := context.Background()
+	drv, err := sql.Open("mysql", dsn)
+	if err != nil {
+		log.Fatalf("failed creating database client: %v", err)
+	}
+	defer drv.Close()
+	client := NewClient(Driver(drv))
+	// creating vertices for the user's edges.
+	pe0 := client.Pet.
+		Create().
+		SetName("string").
+		SaveX(ctx)
+	log.Println("pet created:", pe0)
+
+	// create user vertex with its edges.
+	u := client.User.
+		Create().
+		SetAge(1).
+		SetName("string").
+		AddPets(pe0).
+		SaveX(ctx)
+	log.Println("user created:", u)
+
+	// query edges.
+	pe0, err = u.QueryPets().First(ctx)
+	if err != nil {
+		log.Fatalf("failed querying pets: %v", err)
+	}
+	log.Println("pets found:", pe0)
+
+	// Output:
+}

examples/o2m2types/ent/generate.go

@@ -0,0 +1,3 @@
+package ent
+
+//go:generate go run ../../../entc/cmd/entc/entc.go generate --header "Code generated (@generated) by entc, DO NOT EDIT." ./schema

examples/o2m2types/ent/migrate/migrate.go

@@ -0,0 +1,48 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package migrate
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/facebookincubator/ent/dialect"
+	"github.com/facebookincubator/ent/dialect/sql/schema"
+)
+
+var (
+	// WithGlobalUniqueID sets the universal ids options to the migration.
+	// If this option is enabled, ent migration will allocate a 1<<32 range
+	// for the ids of each entity (table).
+	// Note that this option cannot be applied on tables that already exist.
+	WithGlobalUniqueID = schema.WithGlobalUniqueID
+	// WithDropColumn sets the drop column option to the migration.
+	// If this option is enabled, ent migration will drop old columns
+	// that were used for both fields and edges. This defaults to false.
+	WithDropColumn = schema.WithDropColumn
+	// WithDropIndex sets the drop index option to the migration.
+	// If this option is enabled, ent migration will drop old indexes
+	// that were defined in the schema. This defaults to false.
+	// Note that unique constraints are defined using `UNIQUE INDEX`,
+	// and therefore, it's recommended to enable this option to get more
+	// flexibility in the schema changes.
+	WithDropIndex = schema.WithDropIndex
+)
+
+// Schema is the API for creating, migrating and dropping a schema.
+type Schema struct {
+	drv         dialect.Driver
+	universalID bool
+}
+
+// NewSchema creates a new schema client.
+func NewSchema(drv dialect.Driver) *Schema { return &Schema{drv: drv} }
+
+// Create creates all schema resources.
+func (s *Schema) Create(ctx context.Context, opts ...schema.MigrateOption) error {
+	migrate, err := schema.NewMigrate(s.drv, opts...)
+	if err != nil {
+		return fmt.Errorf("ent/migrate: %v", err)
+	}
+	return migrate.Create(ctx, Tables...)
+}

examples/o2m2types/ent/migrate/schema.go

@@ -0,0 +1,54 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package migrate
+
+import (
+	"github.com/facebookincubator/ent/dialect/sql/schema"
+	"github.com/facebookincubator/ent/schema/field"
+)
+
+var (
+	// PetsColumns holds the columns for the "pets" table.
+	PetsColumns = []*schema.Column{
+		{Name: "id", Type: field.TypeInt, Increment: true},
+		{Name: "name", Type: field.TypeString},
+		{Name: "owner_id", Type: field.TypeInt, Nullable: true},
+	}
+	// PetsTable holds the schema information for the "pets" table.
+	PetsTable = &schema.Table{
+		Name:       "pets",
+		Columns:    PetsColumns,
+		PrimaryKey: []*schema.Column{PetsColumns[0]},
+		ForeignKeys: []*schema.ForeignKey{
+			{
+				Symbol:  "pets_users_pets",
+				Columns: []*schema.Column{PetsColumns[2]},
+
+				RefColumns: []*schema.Column{UsersColumns[0]},
+				OnDelete:   schema.SetNull,
+			},
+		},
+	}
+	// UsersColumns holds the columns for the "users" table.
+	UsersColumns = []*schema.Column{
+		{Name: "id", Type: field.TypeInt, Increment: true},
+		{Name: "age", Type: field.TypeInt},
+		{Name: "name", Type: field.TypeString},
+	}
+	// UsersTable holds the schema information for the "users" table.
+	UsersTable = &schema.Table{
+		Name:        "users",
+		Columns:     UsersColumns,
+		PrimaryKey:  []*schema.Column{UsersColumns[0]},
+		ForeignKeys: []*schema.ForeignKey{},
+	}
+	// Tables holds all the tables in the schema.
+	Tables = []*schema.Table{
+		PetsTable,
+		UsersTable,
+	}
+)
+
+func init() {
+	PetsTable.ForeignKeys[0].RefTable = UsersTable
+}

examples/o2m2types/ent/pet.go

@@ -0,0 +1,91 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// Pet is the model entity for the Pet schema.
+type Pet struct {
+	config
+	// ID of the ent.
+	ID int `json:"id,omitempty"`
+	// Name holds the value of the "name" field.
+	Name string `json:"name,omitempty"`
+}
+
+// FromRows scans the sql response data into Pet.
+func (pe *Pet) FromRows(rows *sql.Rows) error {
+	var vpe struct {
+		ID   int
+		Name sql.NullString
+	}
+	// the order here should be the same as in the `pet.Columns`.
+	if err := rows.Scan(
+		&vpe.ID,
+		&vpe.Name,
+	); err != nil {
+		return err
+	}
+	pe.ID = vpe.ID
+	pe.Name = vpe.Name.String
+	return nil
+}
+
+// QueryOwner queries the owner edge of the Pet.
+func (pe *Pet) QueryOwner() *UserQuery {
+	return (&PetClient{pe.config}).QueryOwner(pe)
+}
+
+// Update returns a builder for updating this Pet.
+// Note that, you need to call Pet.Unwrap() before calling this method, if this Pet
+// was returned from a transaction, and the transaction was committed or rolled back.
+func (pe *Pet) Update() *PetUpdateOne {
+	return (&PetClient{pe.config}).UpdateOne(pe)
+}
+
+// Unwrap unwraps the entity that was returned from a transaction after it was closed,
+// so that all next queries will be executed through the driver which created the transaction.
+func (pe *Pet) Unwrap() *Pet {
+	tx, ok := pe.config.driver.(*txDriver)
+	if !ok {
+		panic("ent: Pet is not a transactional entity")
+	}
+	pe.config.driver = tx.drv
+	return pe
+}
+
+// String implements the fmt.Stringer.
+func (pe *Pet) String() string {
+	buf := bytes.NewBuffer(nil)
+	buf.WriteString("Pet(")
+	buf.WriteString(fmt.Sprintf("id=%v", pe.ID))
+	buf.WriteString(fmt.Sprintf(", name=%v", pe.Name))
+	buf.WriteString(")")
+	return buf.String()
+}
+
+// Pets is a parsable slice of Pet.
+type Pets []*Pet
+
+// FromRows scans the sql response data into Pets.
+func (pe *Pets) FromRows(rows *sql.Rows) error {
+	for rows.Next() {
+		vpe := &Pet{}
+		if err := vpe.FromRows(rows); err != nil {
+			return err
+		}
+		*pe = append(*pe, vpe)
+	}
+	return nil
+}
+
+func (pe Pets) config(cfg config) {
+	for i := range pe {
+		pe[i].config = cfg
+	}
+}

examples/o2m2types/ent/pet/pet.go

@@ -0,0 +1,28 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package pet
+
+const (
+	// Label holds the string label denoting the pet type in the database.
+	Label = "pet"
+	// FieldID holds the string denoting the id field in the database.
+	FieldID = "id"
+	// FieldName holds the string denoting the name vertex property in the database.
+	FieldName = "name"
+
+	// Table holds the table name of the pet in the database.
+	Table = "pets"
+	// OwnerTable is the table the holds the owner relation/edge.
+	OwnerTable = "pets"
+	// OwnerInverseTable is the table name for the User entity.
+	// It exists in this package in order to avoid circular dependency with the "user" package.
+	OwnerInverseTable = "users"
+	// OwnerColumn is the table column denoting the owner relation/edge.
+	OwnerColumn = "owner_id"
+)
+
+// Columns holds all SQL columns are pet fields.
+var Columns = []string{
+	FieldID,
+	FieldName,
+}

examples/o2m2types/ent/pet/where.go

@@ -0,0 +1,305 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package pet
+
+import (
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/predicate"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// ID filters vertices based on their identifier.
+func ID(id int) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.EQ(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDEQ applies the EQ predicate on the ID field.
+func IDEQ(id int) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.EQ(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDNEQ applies the NEQ predicate on the ID field.
+func IDNEQ(id int) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.NEQ(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDGT applies the GT predicate on the ID field.
+func IDGT(id int) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.GT(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDGTE applies the GTE predicate on the ID field.
+func IDGTE(id int) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.GTE(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDLT applies the LT predicate on the ID field.
+func IDLT(id int) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.LT(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDLTE applies the LTE predicate on the ID field.
+func IDLTE(id int) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.LTE(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDIn applies the In predicate on the ID field.
+func IDIn(ids ...int) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			// if not arguments were provided, append the FALSE constants,
+			// since we can't apply "IN ()". This will make this predicate falsy.
+			if len(ids) == 0 {
+				s.Where(sql.False())
+				return
+			}
+			v := make([]interface{}, len(ids))
+			for i := range v {
+				v[i] = ids[i]
+			}
+			s.Where(sql.In(s.C(FieldID), v...))
+		},
+	)
+}
+
+// IDNotIn applies the NotIn predicate on the ID field.
+func IDNotIn(ids ...int) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			// if not arguments were provided, append the FALSE constants,
+			// since we can't apply "IN ()". This will make this predicate falsy.
+			if len(ids) == 0 {
+				s.Where(sql.False())
+				return
+			}
+			v := make([]interface{}, len(ids))
+			for i := range v {
+				v[i] = ids[i]
+			}
+			s.Where(sql.NotIn(s.C(FieldID), v...))
+		},
+	)
+}
+
+// Name applies equality check predicate on the "name" field. It's identical to NameEQ.
+func Name(v string) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.EQ(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameEQ applies the EQ predicate on the "name" field.
+func NameEQ(v string) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.EQ(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameNEQ applies the NEQ predicate on the "name" field.
+func NameNEQ(v string) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.NEQ(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameGT applies the GT predicate on the "name" field.
+func NameGT(v string) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.GT(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameGTE applies the GTE predicate on the "name" field.
+func NameGTE(v string) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.GTE(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameLT applies the LT predicate on the "name" field.
+func NameLT(v string) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.LT(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameLTE applies the LTE predicate on the "name" field.
+func NameLTE(v string) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.LTE(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameIn applies the In predicate on the "name" field.
+func NameIn(vs ...string) predicate.Pet {
+	v := make([]interface{}, len(vs))
+	for i := range v {
+		v[i] = vs[i]
+	}
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			// if not arguments were provided, append the FALSE constants,
+			// since we can't apply "IN ()". This will make this predicate falsy.
+			if len(vs) == 0 {
+				s.Where(sql.False())
+				return
+			}
+			s.Where(sql.In(s.C(FieldName), v...))
+		},
+	)
+}
+
+// NameNotIn applies the NotIn predicate on the "name" field.
+func NameNotIn(vs ...string) predicate.Pet {
+	v := make([]interface{}, len(vs))
+	for i := range v {
+		v[i] = vs[i]
+	}
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			// if not arguments were provided, append the FALSE constants,
+			// since we can't apply "IN ()". This will make this predicate falsy.
+			if len(vs) == 0 {
+				s.Where(sql.False())
+				return
+			}
+			s.Where(sql.NotIn(s.C(FieldName), v...))
+		},
+	)
+}
+
+// NameContains applies the Contains predicate on the "name" field.
+func NameContains(v string) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.Contains(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameHasPrefix applies the HasPrefix predicate on the "name" field.
+func NameHasPrefix(v string) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.HasPrefix(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameHasSuffix applies the HasSuffix predicate on the "name" field.
+func NameHasSuffix(v string) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.HasSuffix(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameContainsFold applies the ContainsFold predicate on the "name" field.
+func NameContainsFold(v string) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			s.Where(sql.ContainsFold(s.C(FieldName), v))
+		},
+	)
+}
+
+// HasOwner applies the HasEdge predicate on the "owner" edge.
+func HasOwner() predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			t1 := s.Table()
+			s.Where(sql.NotNull(t1.C(OwnerColumn)))
+		},
+	)
+}
+
+// HasOwnerWith applies the HasEdge predicate on the "owner" edge with a given conditions (other predicates).
+func HasOwnerWith(preds ...predicate.User) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			t1 := s.Table()
+			t2 := sql.Select(FieldID).From(sql.Table(OwnerInverseTable))
+			for _, p := range preds {
+				p(t2)
+			}
+			s.Where(sql.In(t1.C(OwnerColumn), t2))
+		},
+	)
+}
+
+// And groups list of predicates with the AND operator between them.
+func And(predicates ...predicate.Pet) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			for _, p := range predicates {
+				p(s)
+			}
+		},
+	)
+}
+
+// Or groups list of predicates with the OR operator between them.
+func Or(predicates ...predicate.Pet) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			for i, p := range predicates {
+				if i > 0 {
+					s.Or()
+				}
+				p(s)
+			}
+		},
+	)
+}
+
+// Not applies the not operator on the given predicate.
+func Not(p predicate.Pet) predicate.Pet {
+	return predicate.Pet(
+		func(s *sql.Selector) {
+			p(s.Not())
+		},
+	)
+}

examples/o2m2types/ent/pet_create.go

@@ -0,0 +1,107 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+	"errors"
+
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/pet"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// PetCreate is the builder for creating a Pet entity.
+type PetCreate struct {
+	config
+	name  *string
+	owner map[int]struct{}
+}
+
+// SetName sets the name field.
+func (pc *PetCreate) SetName(s string) *PetCreate {
+	pc.name = &s
+	return pc
+}
+
+// SetOwnerID sets the owner edge to User by id.
+func (pc *PetCreate) SetOwnerID(id int) *PetCreate {
+	if pc.owner == nil {
+		pc.owner = make(map[int]struct{})
+	}
+	pc.owner[id] = struct{}{}
+	return pc
+}
+
+// SetNillableOwnerID sets the owner edge to User by id if the given value is not nil.
+func (pc *PetCreate) SetNillableOwnerID(id *int) *PetCreate {
+	if id != nil {
+		pc = pc.SetOwnerID(*id)
+	}
+	return pc
+}
+
+// SetOwner sets the owner edge to User.
+func (pc *PetCreate) SetOwner(u *User) *PetCreate {
+	return pc.SetOwnerID(u.ID)
+}
+
+// Save creates the Pet in the database.
+func (pc *PetCreate) Save(ctx context.Context) (*Pet, error) {
+	if pc.name == nil {
+		return nil, errors.New("ent: missing required field \"name\"")
+	}
+	if len(pc.owner) > 1 {
+		return nil, errors.New("ent: multiple assignments on a unique edge \"owner\"")
+	}
+	return pc.sqlSave(ctx)
+}
+
+// SaveX calls Save and panics if Save returns an error.
+func (pc *PetCreate) SaveX(ctx context.Context) *Pet {
+	v, err := pc.Save(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
+func (pc *PetCreate) sqlSave(ctx context.Context) (*Pet, error) {
+	var (
+		res sql.Result
+		pe  = &Pet{config: pc.config}
+	)
+	tx, err := pc.driver.Tx(ctx)
+	if err != nil {
+		return nil, err
+	}
+	builder := sql.Insert(pet.Table).Default(pc.driver.Dialect())
+	if pc.name != nil {
+		builder.Set(pet.FieldName, *pc.name)
+		pe.Name = *pc.name
+	}
+	query, args := builder.Query()
+	if err := tx.Exec(ctx, query, args, &res); err != nil {
+		return nil, rollback(tx, err)
+	}
+	id, err := res.LastInsertId()
+	if err != nil {
+		return nil, rollback(tx, err)
+	}
+	pe.ID = int(id)
+	if len(pc.owner) > 0 {
+		for eid := range pc.owner {
+			query, args := sql.Update(pet.OwnerTable).
+				Set(pet.OwnerColumn, eid).
+				Where(sql.EQ(pet.FieldID, id)).
+				Query()
+			if err := tx.Exec(ctx, query, args, &res); err != nil {
+				return nil, rollback(tx, err)
+			}
+		}
+	}
+	if err := tx.Commit(); err != nil {
+		return nil, err
+	}
+	return pe, nil
+}

examples/o2m2types/ent/pet_delete.go

@@ -0,0 +1,61 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/pet"
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/predicate"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// PetDelete is the builder for deleting a Pet entity.
+type PetDelete struct {
+	config
+	predicates []predicate.Pet
+}
+
+// Where adds a new predicate for the builder.
+func (pd *PetDelete) Where(ps ...predicate.Pet) *PetDelete {
+	pd.predicates = append(pd.predicates, ps...)
+	return pd
+}
+
+// Exec executes the deletion query.
+func (pd *PetDelete) Exec(ctx context.Context) error {
+	return pd.sqlExec(ctx)
+}
+
+// ExecX is like Exec, but panics if an error occurs.
+func (pd *PetDelete) ExecX(ctx context.Context) {
+	if err := pd.Exec(ctx); err != nil {
+		panic(err)
+	}
+}
+
+func (pd *PetDelete) sqlExec(ctx context.Context) error {
+	var res sql.Result
+	selector := sql.Select().From(sql.Table(pet.Table))
+	for _, p := range pd.predicates {
+		p(selector)
+	}
+	query, args := sql.Delete(pet.Table).FromSelect(selector).Query()
+	return pd.driver.Exec(ctx, query, args, &res)
+}
+
+// PetDeleteOne is the builder for deleting a single Pet entity.
+type PetDeleteOne struct {
+	pd *PetDelete
+}
+
+// Exec executes the deletion query.
+func (pdo *PetDeleteOne) Exec(ctx context.Context) error {
+	return pdo.pd.Exec(ctx)
+}
+
+// ExecX is like Exec, but panics if an error occurs.
+func (pdo *PetDeleteOne) ExecX(ctx context.Context) {
+	pdo.pd.ExecX(ctx)
+}

examples/o2m2types/ent/pet_query.go

@@ -0,0 +1,483 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"math"
+
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/pet"
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/predicate"
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/user"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// PetQuery is the builder for querying Pet entities.
+type PetQuery struct {
+	config
+	limit      *int
+	offset     *int
+	order      []Order
+	unique     []string
+	predicates []predicate.Pet
+	// intermediate queries.
+	sql *sql.Selector
+}
+
+// Where adds a new predicate for the builder.
+func (pq *PetQuery) Where(ps ...predicate.Pet) *PetQuery {
+	pq.predicates = append(pq.predicates, ps...)
+	return pq
+}
+
+// Limit adds a limit step to the query.
+func (pq *PetQuery) Limit(limit int) *PetQuery {
+	pq.limit = &limit
+	return pq
+}
+
+// Offset adds an offset step to the query.
+func (pq *PetQuery) Offset(offset int) *PetQuery {
+	pq.offset = &offset
+	return pq
+}
+
+// Order adds an order step to the query.
+func (pq *PetQuery) Order(o ...Order) *PetQuery {
+	pq.order = append(pq.order, o...)
+	return pq
+}
+
+// QueryOwner chains the current query on the owner edge.
+func (pq *PetQuery) QueryOwner() *UserQuery {
+	query := &UserQuery{config: pq.config}
+	t1 := sql.Table(user.Table)
+	t2 := pq.sqlQuery()
+	t2.Select(t2.C(pet.OwnerColumn))
+	query.sql = sql.Select(t1.Columns(user.Columns...)...).
+		From(t1).
+		Join(t2).
+		On(t1.C(user.FieldID), t2.C(pet.OwnerColumn))
+	return query
+}
+
+// Get returns a Pet entity by its id.
+func (pq *PetQuery) Get(ctx context.Context, id int) (*Pet, error) {
+	return pq.Where(pet.ID(id)).Only(ctx)
+}
+
+// GetX is like Get, but panics if an error occurs.
+func (pq *PetQuery) GetX(ctx context.Context, id int) *Pet {
+	pe, err := pq.Get(ctx, id)
+	if err != nil {
+		panic(err)
+	}
+	return pe
+}
+
+// First returns the first Pet entity in the query. Returns *ErrNotFound when no pet was found.
+func (pq *PetQuery) First(ctx context.Context) (*Pet, error) {
+	pes, err := pq.Limit(1).All(ctx)
+	if err != nil {
+		return nil, err
+	}
+	if len(pes) == 0 {
+		return nil, &ErrNotFound{pet.Label}
+	}
+	return pes[0], nil
+}
+
+// FirstX is like First, but panics if an error occurs.
+func (pq *PetQuery) FirstX(ctx context.Context) *Pet {
+	pe, err := pq.First(ctx)
+	if err != nil && !IsNotFound(err) {
+		panic(err)
+	}
+	return pe
+}
+
+// FirstID returns the first Pet id in the query. Returns *ErrNotFound when no id was found.
+func (pq *PetQuery) FirstID(ctx context.Context) (id int, err error) {
+	var ids []int
+	if ids, err = pq.Limit(1).IDs(ctx); err != nil {
+		return
+	}
+	if len(ids) == 0 {
+		err = &ErrNotFound{pet.Label}
+		return
+	}
+	return ids[0], nil
+}
+
+// FirstXID is like FirstID, but panics if an error occurs.
+func (pq *PetQuery) FirstXID(ctx context.Context) int {
+	id, err := pq.FirstID(ctx)
+	if err != nil && !IsNotFound(err) {
+		panic(err)
+	}
+	return id
+}
+
+// Only returns the only Pet entity in the query, returns an error if not exactly one entity was returned.
+func (pq *PetQuery) Only(ctx context.Context) (*Pet, error) {
+	pes, err := pq.Limit(2).All(ctx)
+	if err != nil {
+		return nil, err
+	}
+	switch len(pes) {
+	case 1:
+		return pes[0], nil
+	case 0:
+		return nil, &ErrNotFound{pet.Label}
+	default:
+		return nil, &ErrNotSingular{pet.Label}
+	}
+}
+
+// OnlyX is like Only, but panics if an error occurs.
+func (pq *PetQuery) OnlyX(ctx context.Context) *Pet {
+	pe, err := pq.Only(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return pe
+}
+
+// OnlyID returns the only Pet id in the query, returns an error if not exactly one id was returned.
+func (pq *PetQuery) OnlyID(ctx context.Context) (id int, err error) {
+	var ids []int
+	if ids, err = pq.Limit(2).IDs(ctx); err != nil {
+		return
+	}
+	switch len(ids) {
+	case 1:
+		id = ids[0]
+	case 0:
+		err = &ErrNotFound{pet.Label}
+	default:
+		err = &ErrNotSingular{pet.Label}
+	}
+	return
+}
+
+// OnlyXID is like OnlyID, but panics if an error occurs.
+func (pq *PetQuery) OnlyXID(ctx context.Context) int {
+	id, err := pq.OnlyID(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return id
+}
+
+// All executes the query and returns a list of Pets.
+func (pq *PetQuery) All(ctx context.Context) ([]*Pet, error) {
+	return pq.sqlAll(ctx)
+}
+
+// AllX is like All, but panics if an error occurs.
+func (pq *PetQuery) AllX(ctx context.Context) []*Pet {
+	pes, err := pq.All(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return pes
+}
+
+// IDs executes the query and returns a list of Pet ids.
+func (pq *PetQuery) IDs(ctx context.Context) ([]int, error) {
+	return pq.sqlIDs(ctx)
+}
+
+// IDsX is like IDs, but panics if an error occurs.
+func (pq *PetQuery) IDsX(ctx context.Context) []int {
+	ids, err := pq.IDs(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return ids
+}
+
+// Count returns the count of the given query.
+func (pq *PetQuery) Count(ctx context.Context) (int, error) {
+	return pq.sqlCount(ctx)
+}
+
+// CountX is like Count, but panics if an error occurs.
+func (pq *PetQuery) CountX(ctx context.Context) int {
+	count, err := pq.Count(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return count
+}
+
+// Exist returns true if the query has elements in the graph.
+func (pq *PetQuery) Exist(ctx context.Context) (bool, error) {
+	return pq.sqlExist(ctx)
+}
+
+// ExistX is like Exist, but panics if an error occurs.
+func (pq *PetQuery) ExistX(ctx context.Context) bool {
+	exist, err := pq.Exist(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return exist
+}
+
+// Clone returns a duplicate of the query builder, including all associated steps. It can be
+// used to prepare common query builders and use them differently after the clone is made.
+func (pq *PetQuery) Clone() *PetQuery {
+	return &PetQuery{
+		config:     pq.config,
+		limit:      pq.limit,
+		offset:     pq.offset,
+		order:      append([]Order{}, pq.order...),
+		unique:     append([]string{}, pq.unique...),
+		predicates: append([]predicate.Pet{}, pq.predicates...),
+		// clone intermediate queries.
+		sql: pq.sql.Clone(),
+	}
+}
+
+// GroupBy used to group vertices by one or more fields/columns.
+// It is often used with aggregate functions, like: count, max, mean, min, sum.
+//
+// Example:
+//
+//	var v []struct {
+//		Name string `json:"name,omitempty"`
+//		Count int `json:"count,omitempty"`
+//	}
+//
+//	client.Pet.Query().
+//		GroupBy(pet.FieldName).
+//		Aggregate(ent.Count()).
+//		Scan(ctx, &v)
+//
+func (pq *PetQuery) GroupBy(field string, fields ...string) *PetGroupBy {
+	group := &PetGroupBy{config: pq.config}
+	group.fields = append([]string{field}, fields...)
+	group.sql = pq.sqlQuery()
+	return group
+}
+
+func (pq *PetQuery) sqlAll(ctx context.Context) ([]*Pet, error) {
+	rows := &sql.Rows{}
+	selector := pq.sqlQuery()
+	if unique := pq.unique; len(unique) == 0 {
+		selector.Distinct()
+	}
+	query, args := selector.Query()
+	if err := pq.driver.Query(ctx, query, args, rows); err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var pes Pets
+	if err := pes.FromRows(rows); err != nil {
+		return nil, err
+	}
+	pes.config(pq.config)
+	return pes, nil
+}
+
+func (pq *PetQuery) sqlCount(ctx context.Context) (int, error) {
+	rows := &sql.Rows{}
+	selector := pq.sqlQuery()
+	unique := []string{pet.FieldID}
+	if len(pq.unique) > 0 {
+		unique = pq.unique
+	}
+	selector.Count(sql.Distinct(selector.Columns(unique...)...))
+	query, args := selector.Query()
+	if err := pq.driver.Query(ctx, query, args, rows); err != nil {
+		return 0, err
+	}
+	defer rows.Close()
+	if !rows.Next() {
+		return 0, errors.New("ent: no rows found")
+	}
+	var n int
+	if err := rows.Scan(&n); err != nil {
+		return 0, fmt.Errorf("ent: failed reading count: %v", err)
+	}
+	return n, nil
+}
+
+func (pq *PetQuery) sqlExist(ctx context.Context) (bool, error) {
+	n, err := pq.sqlCount(ctx)
+	if err != nil {
+		return false, fmt.Errorf("ent: check existence: %v", err)
+	}
+	return n > 0, nil
+}
+
+func (pq *PetQuery) sqlIDs(ctx context.Context) ([]int, error) {
+	vs, err := pq.sqlAll(ctx)
+	if err != nil {
+		return nil, err
+	}
+	var ids []int
+	for _, v := range vs {
+		ids = append(ids, v.ID)
+	}
+	return ids, nil
+}
+
+func (pq *PetQuery) sqlQuery() *sql.Selector {
+	t1 := sql.Table(pet.Table)
+	selector := sql.Select(t1.Columns(pet.Columns...)...).From(t1)
+	if pq.sql != nil {
+		selector = pq.sql
+		selector.Select(selector.Columns(pet.Columns...)...)
+	}
+	for _, p := range pq.predicates {
+		p(selector)
+	}
+	for _, p := range pq.order {
+		p(selector)
+	}
+	if offset := pq.offset; offset != nil {
+		// limit is mandatory for offset clause. We start
+		// with default value, and override it below if needed.
+		selector.Offset(*offset).Limit(math.MaxInt64)
+	}
+	if limit := pq.limit; limit != nil {
+		selector.Limit(*limit)
+	}
+	return selector
+}
+
+// PetQuery is the builder for group-by Pet entities.
+type PetGroupBy struct {
+	config
+	fields []string
+	fns    []Aggregate
+	// intermediate queries.
+	sql *sql.Selector
+}
+
+// Aggregate adds the given aggregation functions to the group-by query.
+func (pgb *PetGroupBy) Aggregate(fns ...Aggregate) *PetGroupBy {
+	pgb.fns = append(pgb.fns, fns...)
+	return pgb
+}
+
+// Scan applies the group-by query and scan the result into the given value.
+func (pgb *PetGroupBy) Scan(ctx context.Context, v interface{}) error {
+	return pgb.sqlScan(ctx, v)
+}
+
+// ScanX is like Scan, but panics if an error occurs.
+func (pgb *PetGroupBy) ScanX(ctx context.Context, v interface{}) {
+	if err := pgb.Scan(ctx, v); err != nil {
+		panic(err)
+	}
+}
+
+// Strings returns list of strings from group-by. It is only allowed when querying group-by with one field.
+func (pgb *PetGroupBy) Strings(ctx context.Context) ([]string, error) {
+	if len(pgb.fields) > 1 {
+		return nil, errors.New("ent: PetGroupBy.Strings is not achievable when grouping more than 1 field")
+	}
+	var v []string
+	if err := pgb.Scan(ctx, &v); err != nil {
+		return nil, err
+	}
+	return v, nil
+}
+
+// StringsX is like Strings, but panics if an error occurs.
+func (pgb *PetGroupBy) StringsX(ctx context.Context) []string {
+	v, err := pgb.Strings(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
+// Ints returns list of ints from group-by. It is only allowed when querying group-by with one field.
+func (pgb *PetGroupBy) Ints(ctx context.Context) ([]int, error) {
+	if len(pgb.fields) > 1 {
+		return nil, errors.New("ent: PetGroupBy.Ints is not achievable when grouping more than 1 field")
+	}
+	var v []int
+	if err := pgb.Scan(ctx, &v); err != nil {
+		return nil, err
+	}
+	return v, nil
+}
+
+// IntsX is like Ints, but panics if an error occurs.
+func (pgb *PetGroupBy) IntsX(ctx context.Context) []int {
+	v, err := pgb.Ints(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
+// Float64s returns list of float64s from group-by. It is only allowed when querying group-by with one field.
+func (pgb *PetGroupBy) Float64s(ctx context.Context) ([]float64, error) {
+	if len(pgb.fields) > 1 {
+		return nil, errors.New("ent: PetGroupBy.Float64s is not achievable when grouping more than 1 field")
+	}
+	var v []float64
+	if err := pgb.Scan(ctx, &v); err != nil {
+		return nil, err
+	}
+	return v, nil
+}
+
+// Float64sX is like Float64s, but panics if an error occurs.
+func (pgb *PetGroupBy) Float64sX(ctx context.Context) []float64 {
+	v, err := pgb.Float64s(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
+// Bools returns list of bools from group-by. It is only allowed when querying group-by with one field.
+func (pgb *PetGroupBy) Bools(ctx context.Context) ([]bool, error) {
+	if len(pgb.fields) > 1 {
+		return nil, errors.New("ent: PetGroupBy.Bools is not achievable when grouping more than 1 field")
+	}
+	var v []bool
+	if err := pgb.Scan(ctx, &v); err != nil {
+		return nil, err
+	}
+	return v, nil
+}
+
+// BoolsX is like Bools, but panics if an error occurs.
+func (pgb *PetGroupBy) BoolsX(ctx context.Context) []bool {
+	v, err := pgb.Bools(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
+func (pgb *PetGroupBy) sqlScan(ctx context.Context, v interface{}) error {
+	rows := &sql.Rows{}
+	query, args := pgb.sqlQuery().Query()
+	if err := pgb.driver.Query(ctx, query, args, rows); err != nil {
+		return err
+	}
+	defer rows.Close()
+	return sql.ScanSlice(rows, v)
+}
+
+func (pgb *PetGroupBy) sqlQuery() *sql.Selector {
+	selector := pgb.sql
+	columns := make([]string, 0, len(pgb.fields)+len(pgb.fns))
+	columns = append(columns, pgb.fields...)
+	for _, fn := range pgb.fns {
+		columns = append(columns, fn.SQL(selector))
+	}
+	return selector.Select(columns...).GroupBy(pgb.fields...)
+}

examples/o2m2types/ent/pet_update.go

@@ -0,0 +1,307 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/pet"
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/predicate"
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/user"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// PetUpdate is the builder for updating Pet entities.
+type PetUpdate struct {
+	config
+	name         *string
+	owner        map[int]struct{}
+	clearedOwner bool
+	predicates   []predicate.Pet
+}
+
+// Where adds a new predicate for the builder.
+func (pu *PetUpdate) Where(ps ...predicate.Pet) *PetUpdate {
+	pu.predicates = append(pu.predicates, ps...)
+	return pu
+}
+
+// SetName sets the name field.
+func (pu *PetUpdate) SetName(s string) *PetUpdate {
+	pu.name = &s
+	return pu
+}
+
+// SetOwnerID sets the owner edge to User by id.
+func (pu *PetUpdate) SetOwnerID(id int) *PetUpdate {
+	if pu.owner == nil {
+		pu.owner = make(map[int]struct{})
+	}
+	pu.owner[id] = struct{}{}
+	return pu
+}
+
+// SetNillableOwnerID sets the owner edge to User by id if the given value is not nil.
+func (pu *PetUpdate) SetNillableOwnerID(id *int) *PetUpdate {
+	if id != nil {
+		pu = pu.SetOwnerID(*id)
+	}
+	return pu
+}
+
+// SetOwner sets the owner edge to User.
+func (pu *PetUpdate) SetOwner(u *User) *PetUpdate {
+	return pu.SetOwnerID(u.ID)
+}
+
+// ClearOwner clears the owner edge to User.
+func (pu *PetUpdate) ClearOwner() *PetUpdate {
+	pu.clearedOwner = true
+	return pu
+}
+
+// Save executes the query and returns the number of rows/vertices matched by this operation.
+func (pu *PetUpdate) Save(ctx context.Context) (int, error) {
+	if len(pu.owner) > 1 {
+		return 0, errors.New("ent: multiple assignments on a unique edge \"owner\"")
+	}
+	return pu.sqlSave(ctx)
+}
+
+// SaveX is like Save, but panics if an error occurs.
+func (pu *PetUpdate) SaveX(ctx context.Context) int {
+	affected, err := pu.Save(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return affected
+}
+
+// Exec executes the query.
+func (pu *PetUpdate) Exec(ctx context.Context) error {
+	_, err := pu.Save(ctx)
+	return err
+}
+
+// ExecX is like Exec, but panics if an error occurs.
+func (pu *PetUpdate) ExecX(ctx context.Context) {
+	if err := pu.Exec(ctx); err != nil {
+		panic(err)
+	}
+}
+
+func (pu *PetUpdate) sqlSave(ctx context.Context) (n int, err error) {
+	selector := sql.Select(pet.FieldID).From(sql.Table(pet.Table))
+	for _, p := range pu.predicates {
+		p(selector)
+	}
+	rows := &sql.Rows{}
+	query, args := selector.Query()
+	if err = pu.driver.Query(ctx, query, args, rows); err != nil {
+		return 0, err
+	}
+	defer rows.Close()
+	var ids []int
+	for rows.Next() {
+		var id int
+		if err := rows.Scan(&id); err != nil {
+			return 0, fmt.Errorf("ent: failed reading id: %v", err)
+		}
+		ids = append(ids, id)
+	}
+	if len(ids) == 0 {
+		return 0, nil
+	}
+
+	tx, err := pu.driver.Tx(ctx)
+	if err != nil {
+		return 0, err
+	}
+	var (
+		update  bool
+		res     sql.Result
+		builder = sql.Update(pet.Table).Where(sql.InInts(pet.FieldID, ids...))
+	)
+	if pu.name != nil {
+		update = true
+		builder.Set(pet.FieldName, *pu.name)
+	}
+	if update {
+		query, args := builder.Query()
+		if err := tx.Exec(ctx, query, args, &res); err != nil {
+			return 0, rollback(tx, err)
+		}
+	}
+	if pu.clearedOwner {
+		query, args := sql.Update(pet.OwnerTable).
+			SetNull(pet.OwnerColumn).
+			Where(sql.InInts(user.FieldID, ids...)).
+			Query()
+		if err := tx.Exec(ctx, query, args, &res); err != nil {
+			return 0, rollback(tx, err)
+		}
+	}
+	if len(pu.owner) > 0 {
+		for eid := range pu.owner {
+			query, args := sql.Update(pet.OwnerTable).
+				Set(pet.OwnerColumn, eid).
+				Where(sql.InInts(pet.FieldID, ids...)).
+				Query()
+			if err := tx.Exec(ctx, query, args, &res); err != nil {
+				return 0, rollback(tx, err)
+			}
+		}
+	}
+	if err = tx.Commit(); err != nil {
+		return 0, err
+	}
+	return len(ids), nil
+}
+
+// PetUpdateOne is the builder for updating a single Pet entity.
+type PetUpdateOne struct {
+	config
+	id           int
+	name         *string
+	owner        map[int]struct{}
+	clearedOwner bool
+}
+
+// SetName sets the name field.
+func (puo *PetUpdateOne) SetName(s string) *PetUpdateOne {
+	puo.name = &s
+	return puo
+}
+
+// SetOwnerID sets the owner edge to User by id.
+func (puo *PetUpdateOne) SetOwnerID(id int) *PetUpdateOne {
+	if puo.owner == nil {
+		puo.owner = make(map[int]struct{})
+	}
+	puo.owner[id] = struct{}{}
+	return puo
+}
+
+// SetNillableOwnerID sets the owner edge to User by id if the given value is not nil.
+func (puo *PetUpdateOne) SetNillableOwnerID(id *int) *PetUpdateOne {
+	if id != nil {
+		puo = puo.SetOwnerID(*id)
+	}
+	return puo
+}
+
+// SetOwner sets the owner edge to User.
+func (puo *PetUpdateOne) SetOwner(u *User) *PetUpdateOne {
+	return puo.SetOwnerID(u.ID)
+}
+
+// ClearOwner clears the owner edge to User.
+func (puo *PetUpdateOne) ClearOwner() *PetUpdateOne {
+	puo.clearedOwner = true
+	return puo
+}
+
+// Save executes the query and returns the updated entity.
+func (puo *PetUpdateOne) Save(ctx context.Context) (*Pet, error) {
+	if len(puo.owner) > 1 {
+		return nil, errors.New("ent: multiple assignments on a unique edge \"owner\"")
+	}
+	return puo.sqlSave(ctx)
+}
+
+// SaveX is like Save, but panics if an error occurs.
+func (puo *PetUpdateOne) SaveX(ctx context.Context) *Pet {
+	pe, err := puo.Save(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return pe
+}
+
+// Exec executes the query on the entity.
+func (puo *PetUpdateOne) Exec(ctx context.Context) error {
+	_, err := puo.Save(ctx)
+	return err
+}
+
+// ExecX is like Exec, but panics if an error occurs.
+func (puo *PetUpdateOne) ExecX(ctx context.Context) {
+	if err := puo.Exec(ctx); err != nil {
+		panic(err)
+	}
+}
+
+func (puo *PetUpdateOne) sqlSave(ctx context.Context) (pe *Pet, err error) {
+	selector := sql.Select(pet.Columns...).From(sql.Table(pet.Table))
+	pet.ID(puo.id)(selector)
+	rows := &sql.Rows{}
+	query, args := selector.Query()
+	if err = puo.driver.Query(ctx, query, args, rows); err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var ids []int
+	for rows.Next() {
+		var id int
+		pe = &Pet{config: puo.config}
+		if err := pe.FromRows(rows); err != nil {
+			return nil, fmt.Errorf("ent: failed scanning row into Pet: %v", err)
+		}
+		id = pe.ID
+		ids = append(ids, id)
+	}
+	switch n := len(ids); {
+	case n == 0:
+		return nil, fmt.Errorf("ent: Pet not found with id: %v", puo.id)
+	case n > 1:
+		return nil, fmt.Errorf("ent: more than one Pet with the same id: %v", puo.id)
+	}
+
+	tx, err := puo.driver.Tx(ctx)
+	if err != nil {
+		return nil, err
+	}
+	var (
+		update  bool
+		res     sql.Result
+		builder = sql.Update(pet.Table).Where(sql.InInts(pet.FieldID, ids...))
+	)
+	if puo.name != nil {
+		update = true
+		builder.Set(pet.FieldName, *puo.name)
+		pe.Name = *puo.name
+	}
+	if update {
+		query, args := builder.Query()
+		if err := tx.Exec(ctx, query, args, &res); err != nil {
+			return nil, rollback(tx, err)
+		}
+	}
+	if puo.clearedOwner {
+		query, args := sql.Update(pet.OwnerTable).
+			SetNull(pet.OwnerColumn).
+			Where(sql.InInts(user.FieldID, ids...)).
+			Query()
+		if err := tx.Exec(ctx, query, args, &res); err != nil {
+			return nil, rollback(tx, err)
+		}
+	}
+	if len(puo.owner) > 0 {
+		for eid := range puo.owner {
+			query, args := sql.Update(pet.OwnerTable).
+				Set(pet.OwnerColumn, eid).
+				Where(sql.InInts(pet.FieldID, ids...)).
+				Query()
+			if err := tx.Exec(ctx, query, args, &res); err != nil {
+				return nil, rollback(tx, err)
+			}
+		}
+	}
+	if err = tx.Commit(); err != nil {
+		return nil, err
+	}
+	return pe, nil
+}

examples/o2m2types/ent/predicate/predicate.go

@@ -0,0 +1,13 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package predicate
+
+import (
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// Pet is the predicate function for pet builders.
+type Pet func(*sql.Selector)
+
+// User is the predicate function for user builders.
+type User func(*sql.Selector)

examples/o2m2types/ent/schema/pet.go

@@ -0,0 +1,28 @@
+package schema
+
+import (
+	"github.com/facebookincubator/ent"
+	"github.com/facebookincubator/ent/schema/edge"
+	"github.com/facebookincubator/ent/schema/field"
+)
+
+// Pet holds the schema definition for the Pet entity.
+type Pet struct {
+	ent.Schema
+}
+
+// Fields of the Pet.
+func (Pet) Fields() []ent.Field {
+	return []ent.Field{
+		field.String("name"),
+	}
+}
+
+// Edges of the Pet.
+func (Pet) Edges() []ent.Edge {
+	return []ent.Edge{
+		edge.From("owner", User.Type).
+			Ref("pets").
+			Unique(),
+	}
+}

examples/o2m2types/ent/schema/user.go

@@ -0,0 +1,27 @@
+package schema
+
+import (
+	"github.com/facebookincubator/ent"
+	"github.com/facebookincubator/ent/schema/edge"
+	"github.com/facebookincubator/ent/schema/field"
+)
+
+// User holds the schema definition for the User entity.
+type User struct {
+	ent.Schema
+}
+
+// Fields of the User.
+func (User) Fields() []ent.Field {
+	return []ent.Field{
+		field.Int("age"),
+		field.String("name"),
+	}
+}
+
+// Edges of the User.
+func (User) Edges() []ent.Edge {
+	return []ent.Edge{
+		edge.To("pets", Pet.Type),
+	}
+}

examples/o2m2types/ent/tx.go

@@ -0,0 +1,96 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+
+	"github.com/facebookincubator/ent/dialect"
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/migrate"
+)
+
+// Tx is a transactional client that is created by calling Client.Tx().
+type Tx struct {
+	config
+	// Pet is the client for interacting with the Pet builders.
+	Pet *PetClient
+	// User is the client for interacting with the User builders.
+	User *UserClient
+}
+
+// Commit commits the transaction.
+func (tx *Tx) Commit() error {
+	return tx.config.driver.(*txDriver).tx.Commit()
+}
+
+// Rollback rollbacks the transaction.
+func (tx *Tx) Rollback() error {
+	return tx.config.driver.(*txDriver).tx.Rollback()
+}
+
+// Client returns a Client that binds to current transaction.
+func (tx *Tx) Client() *Client {
+	return &Client{
+		config: tx.config,
+		Schema: migrate.NewSchema(tx.driver),
+		Pet:    NewPetClient(tx.config),
+		User:   NewUserClient(tx.config),
+	}
+}
+
+// txDriver wraps the given dialect.Tx with a nop dialect.Driver implementation.
+// The idea is to support transactions without adding any extra code to the builders.
+// When a builder calls to driver.Tx(), it gets the same dialect.Tx instance.
+// Commit and Rollback are nop for the internal builders and the user must call one
+// of them in order to commit or rollback the transaction.
+//
+// If a closed transaction is embedded in one of the generated entities, and the entity
+// applies a query, for example: Pet.QueryXXX(), the query will be executed
+// through the driver which created this transaction.
+//
+// Note that txDriver is not goroutine safe.
+type txDriver struct {
+	// the driver we started the transaction from.
+	drv dialect.Driver
+	// tx is the underlying transaction.
+	tx dialect.Tx
+}
+
+// newTx creates a new transactional driver.
+func newTx(ctx context.Context, drv dialect.Driver) (*txDriver, error) {
+	tx, err := drv.Tx(ctx)
+	if err != nil {
+		return nil, err
+	}
+	return &txDriver{tx: tx, drv: drv}, nil
+}
+
+// Tx returns the transaction wrapper (txDriver) to avoid Commit or Rollback calls
+// from the internal builders. Should be called only by the internal builders.
+func (tx *txDriver) Tx(context.Context) (dialect.Tx, error) { return tx, nil }
+
+// Dialect returns the dialect of the driver we started the transaction from.
+func (tx *txDriver) Dialect() string { return tx.drv.Dialect() }
+
+// Close is a nop close.
+func (*txDriver) Close() error { return nil }
+
+// Commit is a nop commit for the internal builders.
+// User must call `Tx.Commit` in order to commit the transaction.
+func (*txDriver) Commit() error { return nil }
+
+// Rollback is a nop rollback for the internal builders.
+// User must call `Tx.Rollback` in order to rollback the transaction.
+func (*txDriver) Rollback() error { return nil }
+
+// Exec calls tx.Exec.
+func (tx *txDriver) Exec(ctx context.Context, query string, args, v interface{}) error {
+	return tx.tx.Exec(ctx, query, args, v)
+}
+
+// Query calls tx.Query.
+func (tx *txDriver) Query(ctx context.Context, query string, args, v interface{}) error {
+	return tx.tx.Query(ctx, query, args, v)
+}
+
+var _ dialect.Driver = (*txDriver)(nil)

examples/o2m2types/ent/user.go

@@ -0,0 +1,97 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// User is the model entity for the User schema.
+type User struct {
+	config
+	// ID of the ent.
+	ID int `json:"id,omitempty"`
+	// Age holds the value of the "age" field.
+	Age int `json:"age,omitempty"`
+	// Name holds the value of the "name" field.
+	Name string `json:"name,omitempty"`
+}
+
+// FromRows scans the sql response data into User.
+func (u *User) FromRows(rows *sql.Rows) error {
+	var vu struct {
+		ID   int
+		Age  sql.NullInt64
+		Name sql.NullString
+	}
+	// the order here should be the same as in the `user.Columns`.
+	if err := rows.Scan(
+		&vu.ID,
+		&vu.Age,
+		&vu.Name,
+	); err != nil {
+		return err
+	}
+	u.ID = vu.ID
+	u.Age = int(vu.Age.Int64)
+	u.Name = vu.Name.String
+	return nil
+}
+
+// QueryPets queries the pets edge of the User.
+func (u *User) QueryPets() *PetQuery {
+	return (&UserClient{u.config}).QueryPets(u)
+}
+
+// Update returns a builder for updating this User.
+// Note that, you need to call User.Unwrap() before calling this method, if this User
+// was returned from a transaction, and the transaction was committed or rolled back.
+func (u *User) Update() *UserUpdateOne {
+	return (&UserClient{u.config}).UpdateOne(u)
+}
+
+// Unwrap unwraps the entity that was returned from a transaction after it was closed,
+// so that all next queries will be executed through the driver which created the transaction.
+func (u *User) Unwrap() *User {
+	tx, ok := u.config.driver.(*txDriver)
+	if !ok {
+		panic("ent: User is not a transactional entity")
+	}
+	u.config.driver = tx.drv
+	return u
+}
+
+// String implements the fmt.Stringer.
+func (u *User) String() string {
+	buf := bytes.NewBuffer(nil)
+	buf.WriteString("User(")
+	buf.WriteString(fmt.Sprintf("id=%v", u.ID))
+	buf.WriteString(fmt.Sprintf(", age=%v", u.Age))
+	buf.WriteString(fmt.Sprintf(", name=%v", u.Name))
+	buf.WriteString(")")
+	return buf.String()
+}
+
+// Users is a parsable slice of User.
+type Users []*User
+
+// FromRows scans the sql response data into Users.
+func (u *Users) FromRows(rows *sql.Rows) error {
+	for rows.Next() {
+		vu := &User{}
+		if err := vu.FromRows(rows); err != nil {
+			return err
+		}
+		*u = append(*u, vu)
+	}
+	return nil
+}
+
+func (u Users) config(cfg config) {
+	for i := range u {
+		u[i].config = cfg
+	}
+}

examples/o2m2types/ent/user/user.go

@@ -0,0 +1,31 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package user
+
+const (
+	// Label holds the string label denoting the user type in the database.
+	Label = "user"
+	// FieldID holds the string denoting the id field in the database.
+	FieldID = "id"
+	// FieldAge holds the string denoting the age vertex property in the database.
+	FieldAge = "age"
+	// FieldName holds the string denoting the name vertex property in the database.
+	FieldName = "name"
+
+	// Table holds the table name of the user in the database.
+	Table = "users"
+	// PetsTable is the table the holds the pets relation/edge.
+	PetsTable = "pets"
+	// PetsInverseTable is the table name for the Pet entity.
+	// It exists in this package in order to avoid circular dependency with the "pet" package.
+	PetsInverseTable = "pets"
+	// PetsColumn is the table column denoting the pets relation/edge.
+	PetsColumn = "owner_id"
+)
+
+// Columns holds all SQL columns are user fields.
+var Columns = []string{
+	FieldID,
+	FieldAge,
+	FieldName,
+}

examples/o2m2types/ent/user/where.go

@@ -0,0 +1,413 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package user
+
+import (
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/predicate"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// ID filters vertices based on their identifier.
+func ID(id int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.EQ(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDEQ applies the EQ predicate on the ID field.
+func IDEQ(id int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.EQ(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDNEQ applies the NEQ predicate on the ID field.
+func IDNEQ(id int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.NEQ(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDGT applies the GT predicate on the ID field.
+func IDGT(id int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.GT(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDGTE applies the GTE predicate on the ID field.
+func IDGTE(id int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.GTE(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDLT applies the LT predicate on the ID field.
+func IDLT(id int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.LT(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDLTE applies the LTE predicate on the ID field.
+func IDLTE(id int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.LTE(s.C(FieldID), id))
+		},
+	)
+}
+
+// IDIn applies the In predicate on the ID field.
+func IDIn(ids ...int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			// if not arguments were provided, append the FALSE constants,
+			// since we can't apply "IN ()". This will make this predicate falsy.
+			if len(ids) == 0 {
+				s.Where(sql.False())
+				return
+			}
+			v := make([]interface{}, len(ids))
+			for i := range v {
+				v[i] = ids[i]
+			}
+			s.Where(sql.In(s.C(FieldID), v...))
+		},
+	)
+}
+
+// IDNotIn applies the NotIn predicate on the ID field.
+func IDNotIn(ids ...int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			// if not arguments were provided, append the FALSE constants,
+			// since we can't apply "IN ()". This will make this predicate falsy.
+			if len(ids) == 0 {
+				s.Where(sql.False())
+				return
+			}
+			v := make([]interface{}, len(ids))
+			for i := range v {
+				v[i] = ids[i]
+			}
+			s.Where(sql.NotIn(s.C(FieldID), v...))
+		},
+	)
+}
+
+// Age applies equality check predicate on the "age" field. It's identical to AgeEQ.
+func Age(v int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.EQ(s.C(FieldAge), v))
+		},
+	)
+}
+
+// Name applies equality check predicate on the "name" field. It's identical to NameEQ.
+func Name(v string) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.EQ(s.C(FieldName), v))
+		},
+	)
+}
+
+// AgeEQ applies the EQ predicate on the "age" field.
+func AgeEQ(v int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.EQ(s.C(FieldAge), v))
+		},
+	)
+}
+
+// AgeNEQ applies the NEQ predicate on the "age" field.
+func AgeNEQ(v int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.NEQ(s.C(FieldAge), v))
+		},
+	)
+}
+
+// AgeGT applies the GT predicate on the "age" field.
+func AgeGT(v int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.GT(s.C(FieldAge), v))
+		},
+	)
+}
+
+// AgeGTE applies the GTE predicate on the "age" field.
+func AgeGTE(v int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.GTE(s.C(FieldAge), v))
+		},
+	)
+}
+
+// AgeLT applies the LT predicate on the "age" field.
+func AgeLT(v int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.LT(s.C(FieldAge), v))
+		},
+	)
+}
+
+// AgeLTE applies the LTE predicate on the "age" field.
+func AgeLTE(v int) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.LTE(s.C(FieldAge), v))
+		},
+	)
+}
+
+// AgeIn applies the In predicate on the "age" field.
+func AgeIn(vs ...int) predicate.User {
+	v := make([]interface{}, len(vs))
+	for i := range v {
+		v[i] = vs[i]
+	}
+	return predicate.User(
+		func(s *sql.Selector) {
+			// if not arguments were provided, append the FALSE constants,
+			// since we can't apply "IN ()". This will make this predicate falsy.
+			if len(vs) == 0 {
+				s.Where(sql.False())
+				return
+			}
+			s.Where(sql.In(s.C(FieldAge), v...))
+		},
+	)
+}
+
+// AgeNotIn applies the NotIn predicate on the "age" field.
+func AgeNotIn(vs ...int) predicate.User {
+	v := make([]interface{}, len(vs))
+	for i := range v {
+		v[i] = vs[i]
+	}
+	return predicate.User(
+		func(s *sql.Selector) {
+			// if not arguments were provided, append the FALSE constants,
+			// since we can't apply "IN ()". This will make this predicate falsy.
+			if len(vs) == 0 {
+				s.Where(sql.False())
+				return
+			}
+			s.Where(sql.NotIn(s.C(FieldAge), v...))
+		},
+	)
+}
+
+// NameEQ applies the EQ predicate on the "name" field.
+func NameEQ(v string) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.EQ(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameNEQ applies the NEQ predicate on the "name" field.
+func NameNEQ(v string) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.NEQ(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameGT applies the GT predicate on the "name" field.
+func NameGT(v string) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.GT(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameGTE applies the GTE predicate on the "name" field.
+func NameGTE(v string) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.GTE(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameLT applies the LT predicate on the "name" field.
+func NameLT(v string) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.LT(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameLTE applies the LTE predicate on the "name" field.
+func NameLTE(v string) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.LTE(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameIn applies the In predicate on the "name" field.
+func NameIn(vs ...string) predicate.User {
+	v := make([]interface{}, len(vs))
+	for i := range v {
+		v[i] = vs[i]
+	}
+	return predicate.User(
+		func(s *sql.Selector) {
+			// if not arguments were provided, append the FALSE constants,
+			// since we can't apply "IN ()". This will make this predicate falsy.
+			if len(vs) == 0 {
+				s.Where(sql.False())
+				return
+			}
+			s.Where(sql.In(s.C(FieldName), v...))
+		},
+	)
+}
+
+// NameNotIn applies the NotIn predicate on the "name" field.
+func NameNotIn(vs ...string) predicate.User {
+	v := make([]interface{}, len(vs))
+	for i := range v {
+		v[i] = vs[i]
+	}
+	return predicate.User(
+		func(s *sql.Selector) {
+			// if not arguments were provided, append the FALSE constants,
+			// since we can't apply "IN ()". This will make this predicate falsy.
+			if len(vs) == 0 {
+				s.Where(sql.False())
+				return
+			}
+			s.Where(sql.NotIn(s.C(FieldName), v...))
+		},
+	)
+}
+
+// NameContains applies the Contains predicate on the "name" field.
+func NameContains(v string) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.Contains(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameHasPrefix applies the HasPrefix predicate on the "name" field.
+func NameHasPrefix(v string) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.HasPrefix(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameHasSuffix applies the HasSuffix predicate on the "name" field.
+func NameHasSuffix(v string) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.HasSuffix(s.C(FieldName), v))
+		},
+	)
+}
+
+// NameContainsFold applies the ContainsFold predicate on the "name" field.
+func NameContainsFold(v string) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			s.Where(sql.ContainsFold(s.C(FieldName), v))
+		},
+	)
+}
+
+// HasPets applies the HasEdge predicate on the "pets" edge.
+func HasPets() predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			t1 := s.Table()
+			s.Where(
+				sql.In(
+					t1.C(FieldID),
+					sql.Select(PetsColumn).
+						From(sql.Table(PetsTable)).
+						Where(sql.NotNull(PetsColumn)),
+				),
+			)
+		},
+	)
+}
+
+// HasPetsWith applies the HasEdge predicate on the "pets" edge with a given conditions (other predicates).
+func HasPetsWith(preds ...predicate.Pet) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			t1 := s.Table()
+			t2 := sql.Select(PetsColumn).From(sql.Table(PetsTable))
+			for _, p := range preds {
+				p(t2)
+			}
+			s.Where(sql.In(t1.C(FieldID), t2))
+		},
+	)
+}
+
+// And groups list of predicates with the AND operator between them.
+func And(predicates ...predicate.User) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			for _, p := range predicates {
+				p(s)
+			}
+		},
+	)
+}
+
+// Or groups list of predicates with the OR operator between them.
+func Or(predicates ...predicate.User) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			for i, p := range predicates {
+				if i > 0 {
+					s.Or()
+				}
+				p(s)
+			}
+		},
+	)
+}
+
+// Not applies the not operator on the given predicate.
+func Not(p predicate.User) predicate.User {
+	return predicate.User(
+		func(s *sql.Selector) {
+			p(s.Not())
+		},
+	)
+}

examples/o2m2types/ent/user_create.go

@@ -0,0 +1,127 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/pet"
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/user"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// UserCreate is the builder for creating a User entity.
+type UserCreate struct {
+	config
+	age  *int
+	name *string
+	pets map[int]struct{}
+}
+
+// SetAge sets the age field.
+func (uc *UserCreate) SetAge(i int) *UserCreate {
+	uc.age = &i
+	return uc
+}
+
+// SetName sets the name field.
+func (uc *UserCreate) SetName(s string) *UserCreate {
+	uc.name = &s
+	return uc
+}
+
+// AddPetIDs adds the pets edge to Pet by ids.
+func (uc *UserCreate) AddPetIDs(ids ...int) *UserCreate {
+	if uc.pets == nil {
+		uc.pets = make(map[int]struct{})
+	}
+	for i := range ids {
+		uc.pets[ids[i]] = struct{}{}
+	}
+	return uc
+}
+
+// AddPets adds the pets edges to Pet.
+func (uc *UserCreate) AddPets(p ...*Pet) *UserCreate {
+	ids := make([]int, len(p))
+	for i := range p {
+		ids[i] = p[i].ID
+	}
+	return uc.AddPetIDs(ids...)
+}
+
+// Save creates the User in the database.
+func (uc *UserCreate) Save(ctx context.Context) (*User, error) {
+	if uc.age == nil {
+		return nil, errors.New("ent: missing required field \"age\"")
+	}
+	if uc.name == nil {
+		return nil, errors.New("ent: missing required field \"name\"")
+	}
+	return uc.sqlSave(ctx)
+}
+
+// SaveX calls Save and panics if Save returns an error.
+func (uc *UserCreate) SaveX(ctx context.Context) *User {
+	v, err := uc.Save(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
+func (uc *UserCreate) sqlSave(ctx context.Context) (*User, error) {
+	var (
+		res sql.Result
+		u   = &User{config: uc.config}
+	)
+	tx, err := uc.driver.Tx(ctx)
+	if err != nil {
+		return nil, err
+	}
+	builder := sql.Insert(user.Table).Default(uc.driver.Dialect())
+	if uc.age != nil {
+		builder.Set(user.FieldAge, *uc.age)
+		u.Age = *uc.age
+	}
+	if uc.name != nil {
+		builder.Set(user.FieldName, *uc.name)
+		u.Name = *uc.name
+	}
+	query, args := builder.Query()
+	if err := tx.Exec(ctx, query, args, &res); err != nil {
+		return nil, rollback(tx, err)
+	}
+	id, err := res.LastInsertId()
+	if err != nil {
+		return nil, rollback(tx, err)
+	}
+	u.ID = int(id)
+	if len(uc.pets) > 0 {
+		p := sql.P()
+		for eid := range uc.pets {
+			p.Or().EQ(pet.FieldID, eid)
+		}
+		query, args := sql.Update(user.PetsTable).
+			Set(user.PetsColumn, id).
+			Where(sql.And(p, sql.IsNull(user.PetsColumn))).
+			Query()
+		if err := tx.Exec(ctx, query, args, &res); err != nil {
+			return nil, rollback(tx, err)
+		}
+		affected, err := res.RowsAffected()
+		if err != nil {
+			return nil, rollback(tx, err)
+		}
+		if int(affected) < len(uc.pets) {
+			return nil, rollback(tx, &ErrConstraintFailed{msg: fmt.Sprintf("one of \"pets\" %v already connected to a different \"User\"", keys(uc.pets))})
+		}
+	}
+	if err := tx.Commit(); err != nil {
+		return nil, err
+	}
+	return u, nil
+}

examples/o2m2types/ent/user_delete.go

@@ -0,0 +1,61 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/predicate"
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/user"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// UserDelete is the builder for deleting a User entity.
+type UserDelete struct {
+	config
+	predicates []predicate.User
+}
+
+// Where adds a new predicate for the builder.
+func (ud *UserDelete) Where(ps ...predicate.User) *UserDelete {
+	ud.predicates = append(ud.predicates, ps...)
+	return ud
+}
+
+// Exec executes the deletion query.
+func (ud *UserDelete) Exec(ctx context.Context) error {
+	return ud.sqlExec(ctx)
+}
+
+// ExecX is like Exec, but panics if an error occurs.
+func (ud *UserDelete) ExecX(ctx context.Context) {
+	if err := ud.Exec(ctx); err != nil {
+		panic(err)
+	}
+}
+
+func (ud *UserDelete) sqlExec(ctx context.Context) error {
+	var res sql.Result
+	selector := sql.Select().From(sql.Table(user.Table))
+	for _, p := range ud.predicates {
+		p(selector)
+	}
+	query, args := sql.Delete(user.Table).FromSelect(selector).Query()
+	return ud.driver.Exec(ctx, query, args, &res)
+}
+
+// UserDeleteOne is the builder for deleting a single User entity.
+type UserDeleteOne struct {
+	ud *UserDelete
+}
+
+// Exec executes the deletion query.
+func (udo *UserDeleteOne) Exec(ctx context.Context) error {
+	return udo.ud.Exec(ctx)
+}
+
+// ExecX is like Exec, but panics if an error occurs.
+func (udo *UserDeleteOne) ExecX(ctx context.Context) {
+	udo.ud.ExecX(ctx)
+}

examples/o2m2types/ent/user_query.go

@@ -0,0 +1,483 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"math"
+
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/pet"
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/predicate"
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/user"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// UserQuery is the builder for querying User entities.
+type UserQuery struct {
+	config
+	limit      *int
+	offset     *int
+	order      []Order
+	unique     []string
+	predicates []predicate.User
+	// intermediate queries.
+	sql *sql.Selector
+}
+
+// Where adds a new predicate for the builder.
+func (uq *UserQuery) Where(ps ...predicate.User) *UserQuery {
+	uq.predicates = append(uq.predicates, ps...)
+	return uq
+}
+
+// Limit adds a limit step to the query.
+func (uq *UserQuery) Limit(limit int) *UserQuery {
+	uq.limit = &limit
+	return uq
+}
+
+// Offset adds an offset step to the query.
+func (uq *UserQuery) Offset(offset int) *UserQuery {
+	uq.offset = &offset
+	return uq
+}
+
+// Order adds an order step to the query.
+func (uq *UserQuery) Order(o ...Order) *UserQuery {
+	uq.order = append(uq.order, o...)
+	return uq
+}
+
+// QueryPets chains the current query on the pets edge.
+func (uq *UserQuery) QueryPets() *PetQuery {
+	query := &PetQuery{config: uq.config}
+	t1 := sql.Table(pet.Table)
+	t2 := uq.sqlQuery()
+	t2.Select(t2.C(user.FieldID))
+	query.sql = sql.Select().
+		From(t1).
+		Join(t2).
+		On(t1.C(user.PetsColumn), t2.C(user.FieldID))
+	return query
+}
+
+// Get returns a User entity by its id.
+func (uq *UserQuery) Get(ctx context.Context, id int) (*User, error) {
+	return uq.Where(user.ID(id)).Only(ctx)
+}
+
+// GetX is like Get, but panics if an error occurs.
+func (uq *UserQuery) GetX(ctx context.Context, id int) *User {
+	u, err := uq.Get(ctx, id)
+	if err != nil {
+		panic(err)
+	}
+	return u
+}
+
+// First returns the first User entity in the query. Returns *ErrNotFound when no user was found.
+func (uq *UserQuery) First(ctx context.Context) (*User, error) {
+	us, err := uq.Limit(1).All(ctx)
+	if err != nil {
+		return nil, err
+	}
+	if len(us) == 0 {
+		return nil, &ErrNotFound{user.Label}
+	}
+	return us[0], nil
+}
+
+// FirstX is like First, but panics if an error occurs.
+func (uq *UserQuery) FirstX(ctx context.Context) *User {
+	u, err := uq.First(ctx)
+	if err != nil && !IsNotFound(err) {
+		panic(err)
+	}
+	return u
+}
+
+// FirstID returns the first User id in the query. Returns *ErrNotFound when no id was found.
+func (uq *UserQuery) FirstID(ctx context.Context) (id int, err error) {
+	var ids []int
+	if ids, err = uq.Limit(1).IDs(ctx); err != nil {
+		return
+	}
+	if len(ids) == 0 {
+		err = &ErrNotFound{user.Label}
+		return
+	}
+	return ids[0], nil
+}
+
+// FirstXID is like FirstID, but panics if an error occurs.
+func (uq *UserQuery) FirstXID(ctx context.Context) int {
+	id, err := uq.FirstID(ctx)
+	if err != nil && !IsNotFound(err) {
+		panic(err)
+	}
+	return id
+}
+
+// Only returns the only User entity in the query, returns an error if not exactly one entity was returned.
+func (uq *UserQuery) Only(ctx context.Context) (*User, error) {
+	us, err := uq.Limit(2).All(ctx)
+	if err != nil {
+		return nil, err
+	}
+	switch len(us) {
+	case 1:
+		return us[0], nil
+	case 0:
+		return nil, &ErrNotFound{user.Label}
+	default:
+		return nil, &ErrNotSingular{user.Label}
+	}
+}
+
+// OnlyX is like Only, but panics if an error occurs.
+func (uq *UserQuery) OnlyX(ctx context.Context) *User {
+	u, err := uq.Only(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return u
+}
+
+// OnlyID returns the only User id in the query, returns an error if not exactly one id was returned.
+func (uq *UserQuery) OnlyID(ctx context.Context) (id int, err error) {
+	var ids []int
+	if ids, err = uq.Limit(2).IDs(ctx); err != nil {
+		return
+	}
+	switch len(ids) {
+	case 1:
+		id = ids[0]
+	case 0:
+		err = &ErrNotFound{user.Label}
+	default:
+		err = &ErrNotSingular{user.Label}
+	}
+	return
+}
+
+// OnlyXID is like OnlyID, but panics if an error occurs.
+func (uq *UserQuery) OnlyXID(ctx context.Context) int {
+	id, err := uq.OnlyID(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return id
+}
+
+// All executes the query and returns a list of Users.
+func (uq *UserQuery) All(ctx context.Context) ([]*User, error) {
+	return uq.sqlAll(ctx)
+}
+
+// AllX is like All, but panics if an error occurs.
+func (uq *UserQuery) AllX(ctx context.Context) []*User {
+	us, err := uq.All(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return us
+}
+
+// IDs executes the query and returns a list of User ids.
+func (uq *UserQuery) IDs(ctx context.Context) ([]int, error) {
+	return uq.sqlIDs(ctx)
+}
+
+// IDsX is like IDs, but panics if an error occurs.
+func (uq *UserQuery) IDsX(ctx context.Context) []int {
+	ids, err := uq.IDs(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return ids
+}
+
+// Count returns the count of the given query.
+func (uq *UserQuery) Count(ctx context.Context) (int, error) {
+	return uq.sqlCount(ctx)
+}
+
+// CountX is like Count, but panics if an error occurs.
+func (uq *UserQuery) CountX(ctx context.Context) int {
+	count, err := uq.Count(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return count
+}
+
+// Exist returns true if the query has elements in the graph.
+func (uq *UserQuery) Exist(ctx context.Context) (bool, error) {
+	return uq.sqlExist(ctx)
+}
+
+// ExistX is like Exist, but panics if an error occurs.
+func (uq *UserQuery) ExistX(ctx context.Context) bool {
+	exist, err := uq.Exist(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return exist
+}
+
+// Clone returns a duplicate of the query builder, including all associated steps. It can be
+// used to prepare common query builders and use them differently after the clone is made.
+func (uq *UserQuery) Clone() *UserQuery {
+	return &UserQuery{
+		config:     uq.config,
+		limit:      uq.limit,
+		offset:     uq.offset,
+		order:      append([]Order{}, uq.order...),
+		unique:     append([]string{}, uq.unique...),
+		predicates: append([]predicate.User{}, uq.predicates...),
+		// clone intermediate queries.
+		sql: uq.sql.Clone(),
+	}
+}
+
+// GroupBy used to group vertices by one or more fields/columns.
+// It is often used with aggregate functions, like: count, max, mean, min, sum.
+//
+// Example:
+//
+//	var v []struct {
+//		Age int `json:"age,omitempty"`
+//		Count int `json:"count,omitempty"`
+//	}
+//
+//	client.User.Query().
+//		GroupBy(user.FieldAge).
+//		Aggregate(ent.Count()).
+//		Scan(ctx, &v)
+//
+func (uq *UserQuery) GroupBy(field string, fields ...string) *UserGroupBy {
+	group := &UserGroupBy{config: uq.config}
+	group.fields = append([]string{field}, fields...)
+	group.sql = uq.sqlQuery()
+	return group
+}
+
+func (uq *UserQuery) sqlAll(ctx context.Context) ([]*User, error) {
+	rows := &sql.Rows{}
+	selector := uq.sqlQuery()
+	if unique := uq.unique; len(unique) == 0 {
+		selector.Distinct()
+	}
+	query, args := selector.Query()
+	if err := uq.driver.Query(ctx, query, args, rows); err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var us Users
+	if err := us.FromRows(rows); err != nil {
+		return nil, err
+	}
+	us.config(uq.config)
+	return us, nil
+}
+
+func (uq *UserQuery) sqlCount(ctx context.Context) (int, error) {
+	rows := &sql.Rows{}
+	selector := uq.sqlQuery()
+	unique := []string{user.FieldID}
+	if len(uq.unique) > 0 {
+		unique = uq.unique
+	}
+	selector.Count(sql.Distinct(selector.Columns(unique...)...))
+	query, args := selector.Query()
+	if err := uq.driver.Query(ctx, query, args, rows); err != nil {
+		return 0, err
+	}
+	defer rows.Close()
+	if !rows.Next() {
+		return 0, errors.New("ent: no rows found")
+	}
+	var n int
+	if err := rows.Scan(&n); err != nil {
+		return 0, fmt.Errorf("ent: failed reading count: %v", err)
+	}
+	return n, nil
+}
+
+func (uq *UserQuery) sqlExist(ctx context.Context) (bool, error) {
+	n, err := uq.sqlCount(ctx)
+	if err != nil {
+		return false, fmt.Errorf("ent: check existence: %v", err)
+	}
+	return n > 0, nil
+}
+
+func (uq *UserQuery) sqlIDs(ctx context.Context) ([]int, error) {
+	vs, err := uq.sqlAll(ctx)
+	if err != nil {
+		return nil, err
+	}
+	var ids []int
+	for _, v := range vs {
+		ids = append(ids, v.ID)
+	}
+	return ids, nil
+}
+
+func (uq *UserQuery) sqlQuery() *sql.Selector {
+	t1 := sql.Table(user.Table)
+	selector := sql.Select(t1.Columns(user.Columns...)...).From(t1)
+	if uq.sql != nil {
+		selector = uq.sql
+		selector.Select(selector.Columns(user.Columns...)...)
+	}
+	for _, p := range uq.predicates {
+		p(selector)
+	}
+	for _, p := range uq.order {
+		p(selector)
+	}
+	if offset := uq.offset; offset != nil {
+		// limit is mandatory for offset clause. We start
+		// with default value, and override it below if needed.
+		selector.Offset(*offset).Limit(math.MaxInt64)
+	}
+	if limit := uq.limit; limit != nil {
+		selector.Limit(*limit)
+	}
+	return selector
+}
+
+// UserQuery is the builder for group-by User entities.
+type UserGroupBy struct {
+	config
+	fields []string
+	fns    []Aggregate
+	// intermediate queries.
+	sql *sql.Selector
+}
+
+// Aggregate adds the given aggregation functions to the group-by query.
+func (ugb *UserGroupBy) Aggregate(fns ...Aggregate) *UserGroupBy {
+	ugb.fns = append(ugb.fns, fns...)
+	return ugb
+}
+
+// Scan applies the group-by query and scan the result into the given value.
+func (ugb *UserGroupBy) Scan(ctx context.Context, v interface{}) error {
+	return ugb.sqlScan(ctx, v)
+}
+
+// ScanX is like Scan, but panics if an error occurs.
+func (ugb *UserGroupBy) ScanX(ctx context.Context, v interface{}) {
+	if err := ugb.Scan(ctx, v); err != nil {
+		panic(err)
+	}
+}
+
+// Strings returns list of strings from group-by. It is only allowed when querying group-by with one field.
+func (ugb *UserGroupBy) Strings(ctx context.Context) ([]string, error) {
+	if len(ugb.fields) > 1 {
+		return nil, errors.New("ent: UserGroupBy.Strings is not achievable when grouping more than 1 field")
+	}
+	var v []string
+	if err := ugb.Scan(ctx, &v); err != nil {
+		return nil, err
+	}
+	return v, nil
+}
+
+// StringsX is like Strings, but panics if an error occurs.
+func (ugb *UserGroupBy) StringsX(ctx context.Context) []string {
+	v, err := ugb.Strings(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
+// Ints returns list of ints from group-by. It is only allowed when querying group-by with one field.
+func (ugb *UserGroupBy) Ints(ctx context.Context) ([]int, error) {
+	if len(ugb.fields) > 1 {
+		return nil, errors.New("ent: UserGroupBy.Ints is not achievable when grouping more than 1 field")
+	}
+	var v []int
+	if err := ugb.Scan(ctx, &v); err != nil {
+		return nil, err
+	}
+	return v, nil
+}
+
+// IntsX is like Ints, but panics if an error occurs.
+func (ugb *UserGroupBy) IntsX(ctx context.Context) []int {
+	v, err := ugb.Ints(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
+// Float64s returns list of float64s from group-by. It is only allowed when querying group-by with one field.
+func (ugb *UserGroupBy) Float64s(ctx context.Context) ([]float64, error) {
+	if len(ugb.fields) > 1 {
+		return nil, errors.New("ent: UserGroupBy.Float64s is not achievable when grouping more than 1 field")
+	}
+	var v []float64
+	if err := ugb.Scan(ctx, &v); err != nil {
+		return nil, err
+	}
+	return v, nil
+}
+
+// Float64sX is like Float64s, but panics if an error occurs.
+func (ugb *UserGroupBy) Float64sX(ctx context.Context) []float64 {
+	v, err := ugb.Float64s(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
+// Bools returns list of bools from group-by. It is only allowed when querying group-by with one field.
+func (ugb *UserGroupBy) Bools(ctx context.Context) ([]bool, error) {
+	if len(ugb.fields) > 1 {
+		return nil, errors.New("ent: UserGroupBy.Bools is not achievable when grouping more than 1 field")
+	}
+	var v []bool
+	if err := ugb.Scan(ctx, &v); err != nil {
+		return nil, err
+	}
+	return v, nil
+}
+
+// BoolsX is like Bools, but panics if an error occurs.
+func (ugb *UserGroupBy) BoolsX(ctx context.Context) []bool {
+	v, err := ugb.Bools(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
+func (ugb *UserGroupBy) sqlScan(ctx context.Context, v interface{}) error {
+	rows := &sql.Rows{}
+	query, args := ugb.sqlQuery().Query()
+	if err := ugb.driver.Query(ctx, query, args, rows); err != nil {
+		return err
+	}
+	defer rows.Close()
+	return sql.ScanSlice(rows, v)
+}
+
+func (ugb *UserGroupBy) sqlQuery() *sql.Selector {
+	selector := ugb.sql
+	columns := make([]string, 0, len(ugb.fields)+len(ugb.fns))
+	columns = append(columns, ugb.fields...)
+	for _, fn := range ugb.fns {
+		columns = append(columns, fn.SQL(selector))
+	}
+	return selector.Select(columns...).GroupBy(ugb.fields...)
+}

examples/o2m2types/ent/user_update.go

@@ -0,0 +1,379 @@
+// Code generated (@generated) by entc, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/pet"
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/predicate"
+	"github.com/facebookincubator/ent/examples/o2m2types/ent/user"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+)
+
+// UserUpdate is the builder for updating User entities.
+type UserUpdate struct {
+	config
+	age         *int
+	name        *string
+	pets        map[int]struct{}
+	removedPets map[int]struct{}
+	predicates  []predicate.User
+}
+
+// Where adds a new predicate for the builder.
+func (uu *UserUpdate) Where(ps ...predicate.User) *UserUpdate {
+	uu.predicates = append(uu.predicates, ps...)
+	return uu
+}
+
+// SetAge sets the age field.
+func (uu *UserUpdate) SetAge(i int) *UserUpdate {
+	uu.age = &i
+	return uu
+}
+
+// SetName sets the name field.
+func (uu *UserUpdate) SetName(s string) *UserUpdate {
+	uu.name = &s
+	return uu
+}
+
+// AddPetIDs adds the pets edge to Pet by ids.
+func (uu *UserUpdate) AddPetIDs(ids ...int) *UserUpdate {
+	if uu.pets == nil {
+		uu.pets = make(map[int]struct{})
+	}
+	for i := range ids {
+		uu.pets[ids[i]] = struct{}{}
+	}
+	return uu
+}
+
+// AddPets adds the pets edges to Pet.
+func (uu *UserUpdate) AddPets(p ...*Pet) *UserUpdate {
+	ids := make([]int, len(p))
+	for i := range p {
+		ids[i] = p[i].ID
+	}
+	return uu.AddPetIDs(ids...)
+}
+
+// RemovePetIDs removes the pets edge to Pet by ids.
+func (uu *UserUpdate) RemovePetIDs(ids ...int) *UserUpdate {
+	if uu.removedPets == nil {
+		uu.removedPets = make(map[int]struct{})
+	}
+	for i := range ids {
+		uu.removedPets[ids[i]] = struct{}{}
+	}
+	return uu
+}
+
+// RemovePets removes pets edges to Pet.
+func (uu *UserUpdate) RemovePets(p ...*Pet) *UserUpdate {
+	ids := make([]int, len(p))
+	for i := range p {
+		ids[i] = p[i].ID
+	}
+	return uu.RemovePetIDs(ids...)
+}
+
+// Save executes the query and returns the number of rows/vertices matched by this operation.
+func (uu *UserUpdate) Save(ctx context.Context) (int, error) {
+	return uu.sqlSave(ctx)
+}
+
+// SaveX is like Save, but panics if an error occurs.
+func (uu *UserUpdate) SaveX(ctx context.Context) int {
+	affected, err := uu.Save(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return affected
+}
+
+// Exec executes the query.
+func (uu *UserUpdate) Exec(ctx context.Context) error {
+	_, err := uu.Save(ctx)
+	return err
+}
+
+// ExecX is like Exec, but panics if an error occurs.
+func (uu *UserUpdate) ExecX(ctx context.Context) {
+	if err := uu.Exec(ctx); err != nil {
+		panic(err)
+	}
+}
+
+func (uu *UserUpdate) sqlSave(ctx context.Context) (n int, err error) {
+	selector := sql.Select(user.FieldID).From(sql.Table(user.Table))
+	for _, p := range uu.predicates {
+		p(selector)
+	}
+	rows := &sql.Rows{}
+	query, args := selector.Query()
+	if err = uu.driver.Query(ctx, query, args, rows); err != nil {
+		return 0, err
+	}
+	defer rows.Close()
+	var ids []int
+	for rows.Next() {
+		var id int
+		if err := rows.Scan(&id); err != nil {
+			return 0, fmt.Errorf("ent: failed reading id: %v", err)
+		}
+		ids = append(ids, id)
+	}
+	if len(ids) == 0 {
+		return 0, nil
+	}
+
+	tx, err := uu.driver.Tx(ctx)
+	if err != nil {
+		return 0, err
+	}
+	var (
+		update  bool
+		res     sql.Result
+		builder = sql.Update(user.Table).Where(sql.InInts(user.FieldID, ids...))
+	)
+	if uu.age != nil {
+		update = true
+		builder.Set(user.FieldAge, *uu.age)
+	}
+	if uu.name != nil {
+		update = true
+		builder.Set(user.FieldName, *uu.name)
+	}
+	if update {
+		query, args := builder.Query()
+		if err := tx.Exec(ctx, query, args, &res); err != nil {
+			return 0, rollback(tx, err)
+		}
+	}
+	if len(uu.removedPets) > 0 {
+		eids := make([]int, len(uu.removedPets))
+		for eid := range uu.removedPets {
+			eids = append(eids, eid)
+		}
+		query, args := sql.Update(user.PetsTable).
+			SetNull(user.PetsColumn).
+			Where(sql.InInts(user.PetsColumn, ids...)).
+			Where(sql.InInts(pet.FieldID, eids...)).
+			Query()
+		if err := tx.Exec(ctx, query, args, &res); err != nil {
+			return 0, rollback(tx, err)
+		}
+	}
+	if len(uu.pets) > 0 {
+		for _, id := range ids {
+			p := sql.P()
+			for eid := range uu.pets {
+				p.Or().EQ(pet.FieldID, eid)
+			}
+			query, args := sql.Update(user.PetsTable).
+				Set(user.PetsColumn, id).
+				Where(sql.And(p, sql.IsNull(user.PetsColumn))).
+				Query()
+			if err := tx.Exec(ctx, query, args, &res); err != nil {
+				return 0, rollback(tx, err)
+			}
+			affected, err := res.RowsAffected()
+			if err != nil {
+				return 0, rollback(tx, err)
+			}
+			if int(affected) < len(uu.pets) {
+				return 0, rollback(tx, &ErrConstraintFailed{msg: fmt.Sprintf("one of \"pets\" %v already connected to a different \"User\"", keys(uu.pets))})
+			}
+		}
+	}
+	if err = tx.Commit(); err != nil {
+		return 0, err
+	}
+	return len(ids), nil
+}
+
+// UserUpdateOne is the builder for updating a single User entity.
+type UserUpdateOne struct {
+	config
+	id          int
+	age         *int
+	name        *string
+	pets        map[int]struct{}
+	removedPets map[int]struct{}
+}
+
+// SetAge sets the age field.
+func (uuo *UserUpdateOne) SetAge(i int) *UserUpdateOne {
+	uuo.age = &i
+	return uuo
+}
+
+// SetName sets the name field.
+func (uuo *UserUpdateOne) SetName(s string) *UserUpdateOne {
+	uuo.name = &s
+	return uuo
+}
+
+// AddPetIDs adds the pets edge to Pet by ids.
+func (uuo *UserUpdateOne) AddPetIDs(ids ...int) *UserUpdateOne {
+	if uuo.pets == nil {
+		uuo.pets = make(map[int]struct{})
+	}
+	for i := range ids {
+		uuo.pets[ids[i]] = struct{}{}
+	}
+	return uuo
+}
+
+// AddPets adds the pets edges to Pet.
+func (uuo *UserUpdateOne) AddPets(p ...*Pet) *UserUpdateOne {
+	ids := make([]int, len(p))
+	for i := range p {
+		ids[i] = p[i].ID
+	}
+	return uuo.AddPetIDs(ids...)
+}
+
+// RemovePetIDs removes the pets edge to Pet by ids.
+func (uuo *UserUpdateOne) RemovePetIDs(ids ...int) *UserUpdateOne {
+	if uuo.removedPets == nil {
+		uuo.removedPets = make(map[int]struct{})
+	}
+	for i := range ids {
+		uuo.removedPets[ids[i]] = struct{}{}
+	}
+	return uuo
+}
+
+// RemovePets removes pets edges to Pet.
+func (uuo *UserUpdateOne) RemovePets(p ...*Pet) *UserUpdateOne {
+	ids := make([]int, len(p))
+	for i := range p {
+		ids[i] = p[i].ID
+	}
+	return uuo.RemovePetIDs(ids...)
+}
+
+// Save executes the query and returns the updated entity.
+func (uuo *UserUpdateOne) Save(ctx context.Context) (*User, error) {
+	return uuo.sqlSave(ctx)
+}
+
+// SaveX is like Save, but panics if an error occurs.
+func (uuo *UserUpdateOne) SaveX(ctx context.Context) *User {
+	u, err := uuo.Save(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return u
+}
+
+// Exec executes the query on the entity.
+func (uuo *UserUpdateOne) Exec(ctx context.Context) error {
+	_, err := uuo.Save(ctx)
+	return err
+}
+
+// ExecX is like Exec, but panics if an error occurs.
+func (uuo *UserUpdateOne) ExecX(ctx context.Context) {
+	if err := uuo.Exec(ctx); err != nil {
+		panic(err)
+	}
+}
+
+func (uuo *UserUpdateOne) sqlSave(ctx context.Context) (u *User, err error) {
+	selector := sql.Select(user.Columns...).From(sql.Table(user.Table))
+	user.ID(uuo.id)(selector)
+	rows := &sql.Rows{}
+	query, args := selector.Query()
+	if err = uuo.driver.Query(ctx, query, args, rows); err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var ids []int
+	for rows.Next() {
+		var id int
+		u = &User{config: uuo.config}
+		if err := u.FromRows(rows); err != nil {
+			return nil, fmt.Errorf("ent: failed scanning row into User: %v", err)
+		}
+		id = u.ID
+		ids = append(ids, id)
+	}
+	switch n := len(ids); {
+	case n == 0:
+		return nil, fmt.Errorf("ent: User not found with id: %v", uuo.id)
+	case n > 1:
+		return nil, fmt.Errorf("ent: more than one User with the same id: %v", uuo.id)
+	}
+
+	tx, err := uuo.driver.Tx(ctx)
+	if err != nil {
+		return nil, err
+	}
+	var (
+		update  bool
+		res     sql.Result
+		builder = sql.Update(user.Table).Where(sql.InInts(user.FieldID, ids...))
+	)
+	if uuo.age != nil {
+		update = true
+		builder.Set(user.FieldAge, *uuo.age)
+		u.Age = *uuo.age
+	}
+	if uuo.name != nil {
+		update = true
+		builder.Set(user.FieldName, *uuo.name)
+		u.Name = *uuo.name
+	}
+	if update {
+		query, args := builder.Query()
+		if err := tx.Exec(ctx, query, args, &res); err != nil {
+			return nil, rollback(tx, err)
+		}
+	}
+	if len(uuo.removedPets) > 0 {
+		eids := make([]int, len(uuo.removedPets))
+		for eid := range uuo.removedPets {
+			eids = append(eids, eid)
+		}
+		query, args := sql.Update(user.PetsTable).
+			SetNull(user.PetsColumn).
+			Where(sql.InInts(user.PetsColumn, ids...)).
+			Where(sql.InInts(pet.FieldID, eids...)).
+			Query()
+		if err := tx.Exec(ctx, query, args, &res); err != nil {
+			return nil, rollback(tx, err)
+		}
+	}
+	if len(uuo.pets) > 0 {
+		for _, id := range ids {
+			p := sql.P()
+			for eid := range uuo.pets {
+				p.Or().EQ(pet.FieldID, eid)
+			}
+			query, args := sql.Update(user.PetsTable).
+				Set(user.PetsColumn, id).
+				Where(sql.And(p, sql.IsNull(user.PetsColumn))).
+				Query()
+			if err := tx.Exec(ctx, query, args, &res); err != nil {
+				return nil, rollback(tx, err)
+			}
+			affected, err := res.RowsAffected()
+			if err != nil {
+				return nil, rollback(tx, err)
+			}
+			if int(affected) < len(uuo.pets) {
+				return nil, rollback(tx, &ErrConstraintFailed{msg: fmt.Sprintf("one of \"pets\" %v already connected to a different \"User\"", keys(uuo.pets))})
+			}
+		}
+	}
+	if err = tx.Commit(); err != nil {
+		return nil, err
+	}
+	return u, nil
+}

examples/o2m2types/o2m2types.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+
+	"github.com/facebookincubator/ent/examples/o2m2types/ent"
+
+	"github.com/facebookincubator/ent/dialect/sql"
+	_ "github.com/mattn/go-sqlite3"
+)
+
+func main() {
+	db, err := sql.Open("sqlite3", "file:o2o2types?mode=memory&cache=shared&_fk=1")
+	if err != nil {
+		log.Fatalf("failed opening connection to sqlite: %v", err)
+	}
+	defer db.Close()
+	client := ent.NewClient(ent.Driver(db))
+	ctx := context.Background()
+	// run the auto migration tool.
+	if err := client.Schema.Create(ctx); err != nil {
+		log.Fatalf("failed creating schema resources: %v", err)
+	}
+	if err := Do(ctx, client); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func Do(ctx context.Context, client *ent.Client) error {
+	// Create the 2 pets.
+	pedro, err := client.Pet.
+		Create().
+		SetName("pedro").
+		Save(ctx)
+	if err != nil {
+		return fmt.Errorf("creating pet: %v", err)
+	}
+	lola, err := client.Pet.
+		Create().
+		SetName("lola").
+		Save(ctx)
+	if err != nil {
+		return fmt.Errorf("creating pet: %v", err)
+	}
+	// Create the user, and add its pets on the creation.
+	a8m, err := client.User.
+		Create().
+		SetAge(30).
+		SetName("a8m").
+		AddPets(pedro, lola).
+		Save(ctx)
+	if err != nil {
+		return fmt.Errorf("creating user: %v", err)
+	}
+	fmt.Println("User created:", a8m)
+	// Output: User(id=1, age=30, name=a8m)
+
+	// Query the owner. Unlike `Only`, `OnlyX` panics if an error occurs.
+	owner := pedro.QueryOwner().OnlyX(ctx)
+	fmt.Println(owner.Name)
+	// Output: a8m
+
+	// Traverse the sub-graph. Unlike `Count`, `CountX` panics if an error occurs.
+	count := pedro.
+		QueryOwner(). // a8m
+		QueryPets().  // pedro, lola
+		CountX(ctx)   // count
+	fmt.Println(count)
+	// Output: 2
+	return nil
+}