entc/gen/integ: add example for using query modifiers in multischema mode

entc/integration/multischema/ent/config.go

@@ -7,6 +7,8 @@
 package ent
 
 import (
+	"context"
+
 	"entgo.io/ent"
 	"entgo.io/ent/dialect"
 	"entgo.io/ent/entc/integration/multischema/ent/internal"
@@ -67,6 +69,12 @@ func Driver(driver dialect.Driver) Option {
 	}
 }
 
+// SchemaConfigFromContext exports the internal.SchemaConfigFromContext
+// for external usage (inside custom predicates or modifiers).
+func SchemaConfigFromContext(ctx context.Context) SchemaConfig {
+	return internal.SchemaConfigFromContext(ctx)
+}
+
 // SchemaConfig represents alternative schema names for all tables
 // that can be passed at runtime.
 type SchemaConfig = internal.SchemaConfig

entc/integration/multischema/ent/generate.go

@@ -4,4 +4,4 @@
 
 package ent
 
-//go:generate go run -mod=mod entgo.io/ent/cmd/ent generate --feature sql/schemaconfig --header "// Copyright 2019-present Facebook Inc. All rights reserved.\n// This source code is licensed under the Apache 2.0 license found\n// in the LICENSE file in the root directory of this source tree.\n\n// Code generated by entc, DO NOT EDIT." ./schema
+//go:generate go run -mod=mod entgo.io/ent/cmd/ent generate --feature sql/modifier,sql/schemaconfig --template ./template --header "// Copyright 2019-present Facebook Inc. All rights reserved.\n// This source code is licensed under the Apache 2.0 license found\n// in the LICENSE file in the root directory of this source tree.\n\n// Code generated by entc, DO NOT EDIT." ./schema

entc/integration/multischema/ent/group_query.go

@@ -33,6 +33,7 @@ type GroupQuery struct {
 	predicates []predicate.Group
 	// eager-loading edges.
 	withUsers *UserQuery
+	modifiers []func(s *sql.Selector)
 	// intermediate query (i.e. traversal path).
 	sql  *sql.Selector
 	path func(context.Context) (*sql.Selector, error)
@@ -377,6 +378,9 @@ func (gq *GroupQuery) sqlAll(ctx context.Context) ([]*Group, error) {
 	}
 	_spec.Node.Schema = gq.schemaConfig.Group
 	ctx = internal.NewSchemaConfigContext(ctx, gq.schemaConfig)
+	if len(gq.modifiers) > 0 {
+		_spec.Modifiers = gq.modifiers
+	}
 	if err := sqlgraph.QueryNodes(ctx, gq.driver, _spec); err != nil {
 		return nil, err
 	}
@@ -457,6 +461,9 @@ func (gq *GroupQuery) sqlCount(ctx context.Context) (int, error) {
 	_spec := gq.querySpec()
 	_spec.Node.Schema = gq.schemaConfig.Group
 	ctx = internal.NewSchemaConfigContext(ctx, gq.schemaConfig)
+	if len(gq.modifiers) > 0 {
+		_spec.Modifiers = gq.modifiers
+	}
 	_spec.Node.Columns = gq.fields
 	if len(gq.fields) > 0 {
 		_spec.Unique = gq.unique != nil && *gq.unique
@@ -538,6 +545,9 @@ func (gq *GroupQuery) sqlQuery(ctx context.Context) *sql.Selector {
 	t1.Schema(gq.schemaConfig.Group)
 	ctx = internal.NewSchemaConfigContext(ctx, gq.schemaConfig)
 	selector.WithContext(ctx)
+	for _, m := range gq.modifiers {
+		m(selector)
+	}
 	for _, p := range gq.predicates {
 		p(selector)
 	}
@@ -555,6 +565,12 @@ func (gq *GroupQuery) sqlQuery(ctx context.Context) *sql.Selector {
 	return selector
 }
 
+// Modify adds a query modifier for attaching custom logic to queries.
+func (gq *GroupQuery) Modify(modifiers ...func(s *sql.Selector)) *GroupSelect {
+	gq.modifiers = append(gq.modifiers, modifiers...)
+	return gq.Select()
+}
+
 // GroupGroupBy is the group-by builder for Group entities.
 type GroupGroupBy struct {
 	config
@@ -1044,3 +1060,9 @@ func (gs *GroupSelect) sqlScan(ctx context.Context, v interface{}) error {
 	defer rows.Close()
 	return sql.ScanSlice(rows, v)
 }
+
+// Modify adds a query modifier for attaching custom logic to queries.
+func (gs *GroupSelect) Modify(modifiers ...func(s *sql.Selector)) *GroupSelect {
+	gs.modifiers = append(gs.modifiers, modifiers...)
+	return gs
+}

entc/integration/multischema/ent/migrate/schema.go

@@ -27,7 +27,7 @@ var (
 	PetsColumns = []*schema.Column{
 		{Name: "id", Type: field.TypeInt, Increment: true},
 		{Name: "name", Type: field.TypeString, Default: "unknown"},
-		{Name: "user_pets", Type: field.TypeInt, Nullable: true},
+		{Name: "owner_id", Type: field.TypeInt, Nullable: true},
 	}
 	// PetsTable holds the schema information for the "pets" table.
 	PetsTable = &schema.Table{

entc/integration/multischema/ent/mutation.go

@@ -548,9 +548,53 @@ func (m *PetMutation) ResetName() {
 	m.name = nil
 }
 
-// SetOwnerID sets the "owner" edge to the User entity by id.
-func (m *PetMutation) SetOwnerID(id int) {
-	m.owner = &id
+// SetOwnerID sets the "owner_id" field.
+func (m *PetMutation) SetOwnerID(i int) {
+	m.owner = &i
+}
+
+// OwnerID returns the value of the "owner_id" field in the mutation.
+func (m *PetMutation) OwnerID() (r int, exists bool) {
+	v := m.owner
+	if v == nil {
+		return
+	}
+	return *v, true
+}
+
+// OldOwnerID returns the old "owner_id" field's value of the Pet entity.
+// If the Pet object wasn't provided to the builder, the object is fetched from the database.
+// An error is returned if the mutation operation is not UpdateOne, or the database query fails.
+func (m *PetMutation) OldOwnerID(ctx context.Context) (v int, err error) {
+	if !m.op.Is(OpUpdateOne) {
+		return v, fmt.Errorf("OldOwnerID is only allowed on UpdateOne operations")
+	}
+	if m.id == nil || m.oldValue == nil {
+		return v, fmt.Errorf("OldOwnerID requires an ID field in the mutation")
+	}
+	oldValue, err := m.oldValue(ctx)
+	if err != nil {
+		return v, fmt.Errorf("querying old value for OldOwnerID: %w", err)
+	}
+	return oldValue.OwnerID, nil
+}
+
+// ClearOwnerID clears the value of the "owner_id" field.
+func (m *PetMutation) ClearOwnerID() {
+	m.owner = nil
+	m.clearedFields[pet.FieldOwnerID] = struct{}{}
+}
+
+// OwnerIDCleared returns if the "owner_id" field was cleared in this mutation.
+func (m *PetMutation) OwnerIDCleared() bool {
+	_, ok := m.clearedFields[pet.FieldOwnerID]
+	return ok
+}
+
+// ResetOwnerID resets all changes to the "owner_id" field.
+func (m *PetMutation) ResetOwnerID() {
+	m.owner = nil
+	delete(m.clearedFields, pet.FieldOwnerID)
 }
 
 // ClearOwner clears the "owner" edge to the User entity.
@@ -560,15 +604,7 @@ func (m *PetMutation) ClearOwner() {
 
 // OwnerCleared reports if the "owner" edge to the User entity was cleared.
 func (m *PetMutation) OwnerCleared() bool {
-	return m.clearedowner
-}
-
-// OwnerID returns the "owner" edge ID in the mutation.
-func (m *PetMutation) OwnerID() (id int, exists bool) {
-	if m.owner != nil {
-		return *m.owner, true
-	}
-	return
+	return m.OwnerIDCleared() || m.clearedowner
 }
 
 // OwnerIDs returns the "owner" edge IDs in the mutation.
@@ -606,10 +642,13 @@ func (m *PetMutation) Type() string {
 // order to get all numeric fields that were incremented/decremented, call
 // AddedFields().
 func (m *PetMutation) Fields() []string {
-	fields := make([]string, 0, 1)
+	fields := make([]string, 0, 2)
 	if m.name != nil {
 		fields = append(fields, pet.FieldName)
 	}
+	if m.owner != nil {
+		fields = append(fields, pet.FieldOwnerID)
+	}
 	return fields
 }
 
@@ -620,6 +659,8 @@ func (m *PetMutation) Field(name string) (ent.Value, bool) {
 	switch name {
 	case pet.FieldName:
 		return m.Name()
+	case pet.FieldOwnerID:
+		return m.OwnerID()
 	}
 	return nil, false
 }
@@ -631,6 +672,8 @@ func (m *PetMutation) OldField(ctx context.Context, name string) (ent.Value, err
 	switch name {
 	case pet.FieldName:
 		return m.OldName(ctx)
+	case pet.FieldOwnerID:
+		return m.OldOwnerID(ctx)
 	}
 	return nil, fmt.Errorf("unknown Pet field %s", name)
 }
@@ -647,6 +690,13 @@ func (m *PetMutation) SetField(name string, value ent.Value) error {
 		}
 		m.SetName(v)
 		return nil
+	case pet.FieldOwnerID:
+		v, ok := value.(int)
+		if !ok {
+			return fmt.Errorf("unexpected type %T for field %s", value, name)
+		}
+		m.SetOwnerID(v)
+		return nil
 	}
 	return fmt.Errorf("unknown Pet field %s", name)
 }
@@ -654,13 +704,16 @@ func (m *PetMutation) SetField(name string, value ent.Value) error {
 // AddedFields returns all numeric fields that were incremented/decremented during
 // this mutation.
 func (m *PetMutation) AddedFields() []string {
-	return nil
+	var fields []string
+	return fields
 }
 
 // AddedField returns the numeric value that was incremented/decremented on a field
 // with the given name. The second boolean return value indicates that this field
 // was not set, or was not defined in the schema.
 func (m *PetMutation) AddedField(name string) (ent.Value, bool) {
+	switch name {
+	}
 	return nil, false
 }
 
@@ -676,7 +729,11 @@ func (m *PetMutation) AddField(name string, value ent.Value) error {
 // ClearedFields returns all nullable fields that were cleared during this
 // mutation.
 func (m *PetMutation) ClearedFields() []string {
-	return nil
+	var fields []string
+	if m.FieldCleared(pet.FieldOwnerID) {
+		fields = append(fields, pet.FieldOwnerID)
+	}
+	return fields
 }
 
 // FieldCleared returns a boolean indicating if a field with the given name was
@@ -689,6 +746,11 @@ func (m *PetMutation) FieldCleared(name string) bool {
 // ClearField clears the value of the field with the given name. It returns an
 // error if the field is not defined in the schema.
 func (m *PetMutation) ClearField(name string) error {
+	switch name {
+	case pet.FieldOwnerID:
+		m.ClearOwnerID()
+		return nil
+	}
 	return fmt.Errorf("unknown Pet nullable field %s", name)
 }
 
@@ -699,6 +761,9 @@ func (m *PetMutation) ResetField(name string) error {
 	case pet.FieldName:
 		m.ResetName()
 		return nil
+	case pet.FieldOwnerID:
+		m.ResetOwnerID()
+		return nil
 	}
 	return fmt.Errorf("unknown Pet field %s", name)
 }

entc/integration/multischema/ent/pet.go

@@ -22,10 +22,11 @@ type Pet struct {
 	ID int `json:"id,omitempty"`
 	// Name holds the value of the "name" field.
 	Name string `json:"name,omitempty"`
+	// OwnerID holds the value of the "owner_id" field.
+	OwnerID int `json:"owner_id,omitempty"`
 	// Edges holds the relations/edges for other nodes in the graph.
 	// The values are being populated by the PetQuery when eager-loading is set.
-	Edges     PetEdges `json:"edges"`
-	user_pets *int
+	Edges PetEdges `json:"edges"`
 }
 
 // PetEdges holds the relations/edges for other nodes in the graph.
@@ -56,12 +57,10 @@ func (*Pet) scanValues(columns []string) ([]interface{}, error) {
 	values := make([]interface{}, len(columns))
 	for i := range columns {
 		switch columns[i] {
-		case pet.FieldID:
+		case pet.FieldID, pet.FieldOwnerID:
 			values[i] = new(sql.NullInt64)
 		case pet.FieldName:
 			values[i] = new(sql.NullString)
-		case pet.ForeignKeys[0]: // user_pets
-			values[i] = new(sql.NullInt64)
 		default:
 			return nil, fmt.Errorf("unexpected column %q for type Pet", columns[i])
 		}
@@ -89,12 +88,11 @@ func (pe *Pet) assignValues(columns []string, values []interface{}) error {
 			} else if value.Valid {
 				pe.Name = value.String
 			}
-		case pet.ForeignKeys[0]:
+		case pet.FieldOwnerID:
 			if value, ok := values[i].(*sql.NullInt64); !ok {
-				return fmt.Errorf("unexpected type %T for edge-field user_pets", value)
+				return fmt.Errorf("unexpected type %T for field owner_id", values[i])
 			} else if value.Valid {
-				pe.user_pets = new(int)
-				*pe.user_pets = int(value.Int64)
+				pe.OwnerID = int(value.Int64)
 			}
 		}
 	}
@@ -131,6 +129,8 @@ func (pe *Pet) String() string {
 	builder.WriteString(fmt.Sprintf("id=%v", pe.ID))
 	builder.WriteString(", name=")
 	builder.WriteString(pe.Name)
+	builder.WriteString(", owner_id=")
+	builder.WriteString(fmt.Sprintf("%v", pe.OwnerID))
 	builder.WriteByte(')')
 	return builder.String()
 }

entc/integration/multischema/ent/pet/pet.go

@@ -13,6 +13,8 @@ const (
 	FieldID = "id"
 	// FieldName holds the string denoting the name field in the database.
 	FieldName = "name"
+	// FieldOwnerID holds the string denoting the owner_id field in the database.
+	FieldOwnerID = "owner_id"
 	// EdgeOwner holds the string denoting the owner edge name in mutations.
 	EdgeOwner = "owner"
 	// Table holds the table name of the pet in the database.
@@ -23,19 +25,14 @@ const (
 	// 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 = "user_pets"
+	OwnerColumn = "owner_id"
 )
 
 // Columns holds all SQL columns for pet fields.
 var Columns = []string{
 	FieldID,
 	FieldName,
-}
-
-// ForeignKeys holds the SQL foreign-keys that are owned by the "pets"
-// table and are not defined as standalone fields in the schema.
-var ForeignKeys = []string{
-	"user_pets",
+	FieldOwnerID,
 }
 
 // ValidColumn reports if the column name is valid (part of the table columns).
@@ -45,11 +42,6 @@ func ValidColumn(column string) bool {
 			return true
 		}
 	}
-	for i := range ForeignKeys {
-		if column == ForeignKeys[i] {
-			return true
-		}
-	}
 	return false
 }
 

entc/integration/multischema/ent/pet/where.go

@@ -103,6 +103,13 @@ func Name(v string) predicate.Pet {
 	})
 }
 
+// OwnerID applies equality check predicate on the "owner_id" field. It's identical to OwnerIDEQ.
+func OwnerID(v int) predicate.Pet {
+	return predicate.Pet(func(s *sql.Selector) {
+		s.Where(sql.EQ(s.C(FieldOwnerID), v))
+	})
+}
+
 // NameEQ applies the EQ predicate on the "name" field.
 func NameEQ(v string) predicate.Pet {
 	return predicate.Pet(func(s *sql.Selector) {
@@ -214,6 +221,68 @@ func NameContainsFold(v string) predicate.Pet {
 	})
 }
 
+// OwnerIDEQ applies the EQ predicate on the "owner_id" field.
+func OwnerIDEQ(v int) predicate.Pet {
+	return predicate.Pet(func(s *sql.Selector) {
+		s.Where(sql.EQ(s.C(FieldOwnerID), v))
+	})
+}
+
+// OwnerIDNEQ applies the NEQ predicate on the "owner_id" field.
+func OwnerIDNEQ(v int) predicate.Pet {
+	return predicate.Pet(func(s *sql.Selector) {
+		s.Where(sql.NEQ(s.C(FieldOwnerID), v))
+	})
+}
+
+// OwnerIDIn applies the In predicate on the "owner_id" field.
+func OwnerIDIn(vs ...int) 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(v) == 0 {
+			s.Where(sql.False())
+			return
+		}
+		s.Where(sql.In(s.C(FieldOwnerID), v...))
+	})
+}
+
+// OwnerIDNotIn applies the NotIn predicate on the "owner_id" field.
+func OwnerIDNotIn(vs ...int) 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(v) == 0 {
+			s.Where(sql.False())
+			return
+		}
+		s.Where(sql.NotIn(s.C(FieldOwnerID), v...))
+	})
+}
+
+// OwnerIDIsNil applies the IsNil predicate on the "owner_id" field.
+func OwnerIDIsNil() predicate.Pet {
+	return predicate.Pet(func(s *sql.Selector) {
+		s.Where(sql.IsNull(s.C(FieldOwnerID)))
+	})
+}
+
+// OwnerIDNotNil applies the NotNil predicate on the "owner_id" field.
+func OwnerIDNotNil() predicate.Pet {
+	return predicate.Pet(func(s *sql.Selector) {
+		s.Where(sql.NotNull(s.C(FieldOwnerID)))
+	})
+}
+
 // HasOwner applies the HasEdge predicate on the "owner" edge.
 func HasOwner() predicate.Pet {
 	return predicate.Pet(func(s *sql.Selector) {

entc/integration/multischema/ent/pet_create.go

@@ -38,16 +38,16 @@ func (pc *PetCreate) SetNillableName(s *string) *PetCreate {
 	return pc
 }
 
-// SetOwnerID sets the "owner" edge to the User entity by ID.
-func (pc *PetCreate) SetOwnerID(id int) *PetCreate {
-	pc.mutation.SetOwnerID(id)
+// SetOwnerID sets the "owner_id" field.
+func (pc *PetCreate) SetOwnerID(i int) *PetCreate {
+	pc.mutation.SetOwnerID(i)
 	return pc
 }
 
-// SetNillableOwnerID sets the "owner" edge to the User entity by ID if the given value is not nil.
-func (pc *PetCreate) SetNillableOwnerID(id *int) *PetCreate {
-	if id != nil {
-		pc = pc.SetOwnerID(*id)
+// SetNillableOwnerID sets the "owner_id" field if the given value is not nil.
+func (pc *PetCreate) SetNillableOwnerID(i *int) *PetCreate {
+	if i != nil {
+		pc.SetOwnerID(*i)
 	}
 	return pc
 }
@@ -193,7 +193,7 @@ func (pc *PetCreate) createSpec() (*Pet, *sqlgraph.CreateSpec) {
 		for _, k := range nodes {
 			edge.Target.Nodes = append(edge.Target.Nodes, k)
 		}
-		_node.user_pets = &nodes[0]
+		_node.OwnerID = nodes[0]
 		_spec.Edges = append(_spec.Edges, edge)
 	}
 	return _node, _spec

entc/integration/multischema/ent/pet_query.go

@@ -32,7 +32,7 @@ type PetQuery struct {
 	predicates []predicate.Pet
 	// eager-loading edges.
 	withOwner *UserQuery
-	withFKs   bool
+	modifiers []func(s *sql.Selector)
 	// intermediate query (i.e. traversal path).
 	sql  *sql.Selector
 	path func(context.Context) (*sql.Selector, error)
@@ -357,18 +357,11 @@ func (pq *PetQuery) prepareQuery(ctx context.Context) error {
 func (pq *PetQuery) sqlAll(ctx context.Context) ([]*Pet, error) {
 	var (
 		nodes       = []*Pet{}
-		withFKs     = pq.withFKs
 		_spec       = pq.querySpec()
 		loadedTypes = [1]bool{
 			pq.withOwner != nil,
 		}
 	)
-	if pq.withOwner != nil {
-		withFKs = true
-	}
-	if withFKs {
-		_spec.Node.Columns = append(_spec.Node.Columns, pet.ForeignKeys...)
-	}
 	_spec.ScanValues = func(columns []string) ([]interface{}, error) {
 		node := &Pet{config: pq.config}
 		nodes = append(nodes, node)
@@ -384,6 +377,9 @@ func (pq *PetQuery) sqlAll(ctx context.Context) ([]*Pet, error) {
 	}
 	_spec.Node.Schema = pq.schemaConfig.Pet
 	ctx = internal.NewSchemaConfigContext(ctx, pq.schemaConfig)
+	if len(pq.modifiers) > 0 {
+		_spec.Modifiers = pq.modifiers
+	}
 	if err := sqlgraph.QueryNodes(ctx, pq.driver, _spec); err != nil {
 		return nil, err
 	}
@@ -395,10 +391,7 @@ func (pq *PetQuery) sqlAll(ctx context.Context) ([]*Pet, error) {
 		ids := make([]int, 0, len(nodes))
 		nodeids := make(map[int][]*Pet)
 		for i := range nodes {
-			if nodes[i].user_pets == nil {
-				continue
-			}
-			fk := *nodes[i].user_pets
+			fk := nodes[i].OwnerID
 			if _, ok := nodeids[fk]; !ok {
 				ids = append(ids, fk)
 			}
@@ -412,7 +405,7 @@ func (pq *PetQuery) sqlAll(ctx context.Context) ([]*Pet, error) {
 		for _, n := range neighbors {
 			nodes, ok := nodeids[n.ID]
 			if !ok {
-				return nil, fmt.Errorf(`unexpected foreign-key "user_pets" returned %v`, n.ID)
+				return nil, fmt.Errorf(`unexpected foreign-key "owner_id" returned %v`, n.ID)
 			}
 			for i := range nodes {
 				nodes[i].Edges.Owner = n
@@ -427,6 +420,9 @@ func (pq *PetQuery) sqlCount(ctx context.Context) (int, error) {
 	_spec := pq.querySpec()
 	_spec.Node.Schema = pq.schemaConfig.Pet
 	ctx = internal.NewSchemaConfigContext(ctx, pq.schemaConfig)
+	if len(pq.modifiers) > 0 {
+		_spec.Modifiers = pq.modifiers
+	}
 	_spec.Node.Columns = pq.fields
 	if len(pq.fields) > 0 {
 		_spec.Unique = pq.unique != nil && *pq.unique
@@ -508,6 +504,9 @@ func (pq *PetQuery) sqlQuery(ctx context.Context) *sql.Selector {
 	t1.Schema(pq.schemaConfig.Pet)
 	ctx = internal.NewSchemaConfigContext(ctx, pq.schemaConfig)
 	selector.WithContext(ctx)
+	for _, m := range pq.modifiers {
+		m(selector)
+	}
 	for _, p := range pq.predicates {
 		p(selector)
 	}
@@ -525,6 +524,12 @@ func (pq *PetQuery) sqlQuery(ctx context.Context) *sql.Selector {
 	return selector
 }
 
+// Modify adds a query modifier for attaching custom logic to queries.
+func (pq *PetQuery) Modify(modifiers ...func(s *sql.Selector)) *PetSelect {
+	pq.modifiers = append(pq.modifiers, modifiers...)
+	return pq.Select()
+}
+
 // PetGroupBy is the group-by builder for Pet entities.
 type PetGroupBy struct {
 	config
@@ -1014,3 +1019,9 @@ func (ps *PetSelect) sqlScan(ctx context.Context, v interface{}) error {
 	defer rows.Close()
 	return sql.ScanSlice(rows, v)
 }
+
+// Modify adds a query modifier for attaching custom logic to queries.
+func (ps *PetSelect) Modify(modifiers ...func(s *sql.Selector)) *PetSelect {
+	ps.modifiers = append(ps.modifiers, modifiers...)
+	return ps
+}

entc/integration/multischema/ent/pet_update.go

@@ -47,20 +47,26 @@ func (pu *PetUpdate) SetNillableName(s *string) *PetUpdate {
 	return pu
 }
 
-// SetOwnerID sets the "owner" edge to the User entity by ID.
-func (pu *PetUpdate) SetOwnerID(id int) *PetUpdate {
-	pu.mutation.SetOwnerID(id)
+// SetOwnerID sets the "owner_id" field.
+func (pu *PetUpdate) SetOwnerID(i int) *PetUpdate {
+	pu.mutation.SetOwnerID(i)
 	return pu
 }
 
-// SetNillableOwnerID sets the "owner" edge to the User entity by ID if the given value is not nil.
-func (pu *PetUpdate) SetNillableOwnerID(id *int) *PetUpdate {
-	if id != nil {
-		pu = pu.SetOwnerID(*id)
+// SetNillableOwnerID sets the "owner_id" field if the given value is not nil.
+func (pu *PetUpdate) SetNillableOwnerID(i *int) *PetUpdate {
+	if i != nil {
+		pu.SetOwnerID(*i)
 	}
 	return pu
 }
 
+// ClearOwnerID clears the value of the "owner_id" field.
+func (pu *PetUpdate) ClearOwnerID() *PetUpdate {
+	pu.mutation.ClearOwnerID()
+	return pu
+}
+
 // SetOwner sets the "owner" edge to the User entity.
 func (pu *PetUpdate) SetOwner(u *User) *PetUpdate {
 	return pu.SetOwnerID(u.ID)
@@ -228,20 +234,26 @@ func (puo *PetUpdateOne) SetNillableName(s *string) *PetUpdateOne {
 	return puo
 }
 
-// SetOwnerID sets the "owner" edge to the User entity by ID.
-func (puo *PetUpdateOne) SetOwnerID(id int) *PetUpdateOne {
-	puo.mutation.SetOwnerID(id)
+// SetOwnerID sets the "owner_id" field.
+func (puo *PetUpdateOne) SetOwnerID(i int) *PetUpdateOne {
+	puo.mutation.SetOwnerID(i)
 	return puo
 }
 
-// SetNillableOwnerID sets the "owner" edge to the User entity by ID if the given value is not nil.
-func (puo *PetUpdateOne) SetNillableOwnerID(id *int) *PetUpdateOne {
-	if id != nil {
-		puo = puo.SetOwnerID(*id)
+// SetNillableOwnerID sets the "owner_id" field if the given value is not nil.
+func (puo *PetUpdateOne) SetNillableOwnerID(i *int) *PetUpdateOne {
+	if i != nil {
+		puo.SetOwnerID(*i)
 	}
 	return puo
 }
 
+// ClearOwnerID clears the value of the "owner_id" field.
+func (puo *PetUpdateOne) ClearOwnerID() *PetUpdateOne {
+	puo.mutation.ClearOwnerID()
+	return puo
+}
+
 // SetOwner sets the "owner" edge to the User entity.
 func (puo *PetUpdateOne) SetOwner(u *User) *PetUpdateOne {
 	return puo.SetOwnerID(u.ID)

entc/integration/multischema/ent/schema/pet.go

@@ -20,6 +20,8 @@ func (Pet) Fields() []ent.Field {
 	return []ent.Field{
 		field.String("name").
 			Default("unknown"),
+		field.Int("owner_id").
+			Optional(),
 	}
 }
 
@@ -28,6 +30,7 @@ func (Pet) Edges() []ent.Edge {
 	return []ent.Edge{
 		edge.From("owner", User.Type).
 			Ref("pets").
+			Field("owner_id").
 			Unique(),
 	}
 }

entc/integration/multischema/ent/template/config.tmpl

@@ -0,0 +1,16 @@
+{{/*
+Copyright 2019-present Facebook Inc. All rights reserved.
+This source code is licensed under the Apache 2.0 license found
+in the LICENSE file in the root directory of this source tree.
+*/}}
+
+{{/* The line below tells Intellij/GoLand to enable the autocompletion based *gen.Graph type. */}}
+{{/* gotype: entgo.io/ent/entc/gen.Graph */}}
+
+{{ define "config/options/schemaconfig" }}
+// SchemaConfigFromContext exports the internal.SchemaConfigFromContext
+// for external usage (inside custom predicates or modifiers).
+func SchemaConfigFromContext(ctx context.Context) SchemaConfig {
+	return internal.SchemaConfigFromContext(ctx)
+}
+{{ end }}

entc/integration/multischema/ent/user/user.go

@@ -25,7 +25,7 @@ const (
 	// 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 = "user_pets"
+	PetsColumn = "owner_id"
 	// GroupsTable is the table that holds the groups relation/edge. The primary key declared below.
 	GroupsTable = "group_users"
 	// GroupsInverseTable is the table name for the Group entity.

entc/integration/multischema/ent/user_query.go

@@ -35,6 +35,7 @@ type UserQuery struct {
 	// eager-loading edges.
 	withPets   *PetQuery
 	withGroups *GroupQuery
+	modifiers  []func(s *sql.Selector)
 	// intermediate query (i.e. traversal path).
 	sql  *sql.Selector
 	path func(context.Context) (*sql.Selector, error)
@@ -417,6 +418,9 @@ func (uq *UserQuery) sqlAll(ctx context.Context) ([]*User, error) {
 	}
 	_spec.Node.Schema = uq.schemaConfig.User
 	ctx = internal.NewSchemaConfigContext(ctx, uq.schemaConfig)
+	if len(uq.modifiers) > 0 {
+		_spec.Modifiers = uq.modifiers
+	}
 	if err := sqlgraph.QueryNodes(ctx, uq.driver, _spec); err != nil {
 		return nil, err
 	}
@@ -432,7 +436,6 @@ func (uq *UserQuery) sqlAll(ctx context.Context) ([]*User, error) {
 			nodeids[nodes[i].ID] = nodes[i]
 			nodes[i].Edges.Pets = []*Pet{}
 		}
-		query.withFKs = true
 		query.Where(predicate.Pet(func(s *sql.Selector) {
 			s.Where(sql.InValues(user.PetsColumn, fks...))
 		}))
@@ -441,13 +444,10 @@ func (uq *UserQuery) sqlAll(ctx context.Context) ([]*User, error) {
 			return nil, err
 		}
 		for _, n := range neighbors {
-			fk := n.user_pets
-			if fk == nil {
-				return nil, fmt.Errorf(`foreign-key "user_pets" is nil for node %v`, n.ID)
-			}
-			node, ok := nodeids[*fk]
+			fk := n.OwnerID
+			node, ok := nodeids[fk]
 			if !ok {
-				return nil, fmt.Errorf(`unexpected foreign-key "user_pets" returned %v for node %v`, *fk, n.ID)
+				return nil, fmt.Errorf(`unexpected foreign-key "owner_id" returned %v for node %v`, fk, n.ID)
 			}
 			node.Edges.Pets = append(node.Edges.Pets, n)
 		}
@@ -526,6 +526,9 @@ func (uq *UserQuery) sqlCount(ctx context.Context) (int, error) {
 	_spec := uq.querySpec()
 	_spec.Node.Schema = uq.schemaConfig.User
 	ctx = internal.NewSchemaConfigContext(ctx, uq.schemaConfig)
+	if len(uq.modifiers) > 0 {
+		_spec.Modifiers = uq.modifiers
+	}
 	_spec.Node.Columns = uq.fields
 	if len(uq.fields) > 0 {
 		_spec.Unique = uq.unique != nil && *uq.unique
@@ -607,6 +610,9 @@ func (uq *UserQuery) sqlQuery(ctx context.Context) *sql.Selector {
 	t1.Schema(uq.schemaConfig.User)
 	ctx = internal.NewSchemaConfigContext(ctx, uq.schemaConfig)
 	selector.WithContext(ctx)
+	for _, m := range uq.modifiers {
+		m(selector)
+	}
 	for _, p := range uq.predicates {
 		p(selector)
 	}
@@ -624,6 +630,12 @@ func (uq *UserQuery) sqlQuery(ctx context.Context) *sql.Selector {
 	return selector
 }
 
+// Modify adds a query modifier for attaching custom logic to queries.
+func (uq *UserQuery) Modify(modifiers ...func(s *sql.Selector)) *UserSelect {
+	uq.modifiers = append(uq.modifiers, modifiers...)
+	return uq.Select()
+}
+
 // UserGroupBy is the group-by builder for User entities.
 type UserGroupBy struct {
 	config
@@ -1113,3 +1125,9 @@ func (us *UserSelect) sqlScan(ctx context.Context, v interface{}) error {
 	defer rows.Close()
 	return sql.ScanSlice(rows, v)
 }
+
+// Modify adds a query modifier for attaching custom logic to queries.
+func (us *UserSelect) Modify(modifiers ...func(s *sql.Selector)) *UserSelect {
+	us.modifiers = append(us.modifiers, modifiers...)
+	return us
+}

entc/integration/multischema/multischema_test.go

@@ -45,7 +45,29 @@ func TestMySQL(t *testing.T) {
 		client.Group.Create().SetName("GitHub"),
 		client.Group.Create().SetName("GitLab"),
 	).SaveX(ctx)
-	usr := client.User.Create().AddPets(pedro).AddGroups(groups...).SaveX(ctx)
+	usr := client.User.Create().SetName("a8m").AddPets(pedro).AddGroups(groups...).SaveX(ctx)
+
+	// Custom modifier with schema config.
+	var names []struct {
+		User string `sql:"user_name"`
+		Pet  string `sql:"pet_name"`
+	}
+	client.Pet.Query().
+		Modify(func(s *sql.Selector) {
+			// The below function is exported using a custom
+			// template defined in ent/template/config.tmpl.
+			cfg := ent.SchemaConfigFromContext(s.Context())
+			t := sql.Table(user.Table).Schema(cfg.User)
+			s.Join(t).On(s.C(pet.FieldOwnerID), t.C(user.FieldID))
+			s.Select(
+				sql.As(t.C(user.FieldName), "user_name"),
+				sql.As(s.C(pet.FieldName), "pet_name"),
+			)
+		}).
+		ScanX(ctx, &names)
+	require.Len(t, names, 1)
+	require.Equal(t, "a8m", names[0].User)
+	require.Equal(t, "Pedro", names[0].Pet)
 
 	id := client.Group.Query().
 		Where(group.HasUsersWith(user.ID(usr.ID))).