entc/gen: lazy compute storage-driver queries (#408)

examples/o2m2types/ent/client.go

@@ -190,14 +190,16 @@ func (c *PetClient) GetX(ctx context.Context, id int) *Pet {
 // QueryOwner queries the owner edge of a Pet.
 func (c *PetClient) QueryOwner(pe *Pet) *UserQuery {
 	query := &UserQuery{config: c.config}
-	id := pe.ID
-	step := sqlgraph.NewStep(
-		sqlgraph.From(pet.Table, pet.FieldID, id),
-		sqlgraph.To(user.Table, user.FieldID),
-		sqlgraph.Edge(sqlgraph.M2O, true, pet.OwnerTable, pet.OwnerColumn),
-	)
-	query.sql = sqlgraph.Neighbors(pe.driver.Dialect(), step)
-
+	query.path = func(ctx context.Context) (fromV *sql.Selector, _ error) {
+		id := pe.ID
+		step := sqlgraph.NewStep(
+			sqlgraph.From(pet.Table, pet.FieldID, id),
+			sqlgraph.To(user.Table, user.FieldID),
+			sqlgraph.Edge(sqlgraph.M2O, true, pet.OwnerTable, pet.OwnerColumn),
+		)
+		fromV = sqlgraph.Neighbors(pe.driver.Dialect(), step)
+		return fromV, nil
+	}
 	return query
 }
 
@@ -287,14 +289,16 @@ func (c *UserClient) GetX(ctx context.Context, id int) *User {
 // QueryPets queries the pets edge of a User.
 func (c *UserClient) QueryPets(u *User) *PetQuery {
 	query := &PetQuery{config: c.config}
-	id := u.ID
-	step := sqlgraph.NewStep(
-		sqlgraph.From(user.Table, user.FieldID, id),
-		sqlgraph.To(pet.Table, pet.FieldID),
-		sqlgraph.Edge(sqlgraph.O2M, false, user.PetsTable, user.PetsColumn),
-	)
-	query.sql = sqlgraph.Neighbors(u.driver.Dialect(), step)
-
+	query.path = func(ctx context.Context) (fromV *sql.Selector, _ error) {
+		id := u.ID
+		step := sqlgraph.NewStep(
+			sqlgraph.From(user.Table, user.FieldID, id),
+			sqlgraph.To(pet.Table, pet.FieldID),
+			sqlgraph.Edge(sqlgraph.O2M, false, user.PetsTable, user.PetsColumn),
+		)
+		fromV = sqlgraph.Neighbors(u.driver.Dialect(), step)
+		return fromV, nil
+	}
 	return query
 }
 

examples/o2m2types/ent/pet_query.go

@@ -31,8 +31,9 @@ type PetQuery struct {
 	// eager-loading edges.
 	withOwner *UserQuery
 	withFKs   bool
-	// intermediate query.
-	sql *sql.Selector
+	// intermediate query (i.e. traversal path).
+	sql  *sql.Selector
+	path func(context.Context) (*sql.Selector, error)
 }
 
 // Where adds a new predicate for the builder.
@@ -62,12 +63,18 @@ func (pq *PetQuery) Order(o ...Order) *PetQuery {
 // QueryOwner chains the current query on the owner edge.
 func (pq *PetQuery) QueryOwner() *UserQuery {
 	query := &UserQuery{config: pq.config}
-	step := sqlgraph.NewStep(
-		sqlgraph.From(pet.Table, pet.FieldID, pq.sqlQuery()),
-		sqlgraph.To(user.Table, user.FieldID),
-		sqlgraph.Edge(sqlgraph.M2O, true, pet.OwnerTable, pet.OwnerColumn),
-	)
-	query.sql = sqlgraph.SetNeighbors(pq.driver.Dialect(), step)
+	query.path = func(ctx context.Context) (fromU *sql.Selector, err error) {
+		if err := pq.prepareQuery(ctx); err != nil {
+			return nil, err
+		}
+		step := sqlgraph.NewStep(
+			sqlgraph.From(pet.Table, pet.FieldID, pq.sqlQuery()),
+			sqlgraph.To(user.Table, user.FieldID),
+			sqlgraph.Edge(sqlgraph.M2O, true, pet.OwnerTable, pet.OwnerColumn),
+		)
+		fromU = sqlgraph.SetNeighbors(pq.driver.Dialect(), step)
+		return fromU, nil
+	}
 	return query
 }
 
@@ -167,6 +174,9 @@ func (pq *PetQuery) OnlyXID(ctx context.Context) int {
 
 // All executes the query and returns a list of Pets.
 func (pq *PetQuery) All(ctx context.Context) ([]*Pet, error) {
+	if err := pq.prepareQuery(ctx); err != nil {
+		return nil, err
+	}
 	return pq.sqlAll(ctx)
 }
 
@@ -199,6 +209,9 @@ func (pq *PetQuery) IDsX(ctx context.Context) []int {
 
 // Count returns the count of the given query.
 func (pq *PetQuery) Count(ctx context.Context) (int, error) {
+	if err := pq.prepareQuery(ctx); err != nil {
+		return 0, err
+	}
 	return pq.sqlCount(ctx)
 }
 
@@ -213,6 +226,9 @@ func (pq *PetQuery) CountX(ctx context.Context) int {
 
 // Exist returns true if the query has elements in the graph.
 func (pq *PetQuery) Exist(ctx context.Context) (bool, error) {
+	if err := pq.prepareQuery(ctx); err != nil {
+		return false, err
+	}
 	return pq.sqlExist(ctx)
 }
 
@@ -236,7 +252,8 @@ func (pq *PetQuery) Clone() *PetQuery {
 		unique:     append([]string{}, pq.unique...),
 		predicates: append([]predicate.Pet{}, pq.predicates...),
 		// clone intermediate query.
-		sql: pq.sql.Clone(),
+		sql:  pq.sql.Clone(),
+		path: pq.path,
 	}
 }
 
@@ -269,7 +286,12 @@ func (pq *PetQuery) WithOwner(opts ...func(*UserQuery)) *PetQuery {
 func (pq *PetQuery) GroupBy(field string, fields ...string) *PetGroupBy {
 	group := &PetGroupBy{config: pq.config}
 	group.fields = append([]string{field}, fields...)
-	group.sql = pq.sqlQuery()
+	group.path = func(ctx context.Context) (prev *sql.Selector, err error) {
+		if err := pq.prepareQuery(ctx); err != nil {
+			return nil, err
+		}
+		return pq.sqlQuery(), nil
+	}
 	return group
 }
 
@@ -288,10 +310,27 @@ func (pq *PetQuery) GroupBy(field string, fields ...string) *PetGroupBy {
 func (pq *PetQuery) Select(field string, fields ...string) *PetSelect {
 	selector := &PetSelect{config: pq.config}
 	selector.fields = append([]string{field}, fields...)
-	selector.sql = pq.sqlQuery()
+	selector.path = func(ctx context.Context) (prev *sql.Selector, err error) {
+		if err := pq.prepareQuery(ctx); err != nil {
+			return nil, err
+		}
+		return pq.sqlQuery(), nil
+	}
 	return selector
 }
 
+func (pq *PetQuery) prepareQuery(ctx context.Context) error {
+	if pq.path != nil {
+		prev, err := pq.path(ctx)
+		if err != nil {
+			return err
+		}
+		pq.sql = prev
+	}
+	// Privacy and query checks go here.
+	return nil
+}
+
 func (pq *PetQuery) sqlAll(ctx context.Context) ([]*Pet, error) {
 	var (
 		nodes       = []*Pet{}
@@ -438,8 +477,9 @@ type PetGroupBy struct {
 	config
 	fields []string
 	fns    []Aggregate
-	// intermediate query.
-	sql *sql.Selector
+	// intermediate query (i.e. traversal path).
+	sql  *sql.Selector
+	path func(context.Context) (*sql.Selector, error)
 }
 
 // Aggregate adds the given aggregation functions to the group-by query.
@@ -450,6 +490,11 @@ func (pgb *PetGroupBy) Aggregate(fns ...Aggregate) *PetGroupBy {
 
 // Scan applies the group-by query and scan the result into the given value.
 func (pgb *PetGroupBy) Scan(ctx context.Context, v interface{}) error {
+	query, err := pgb.path(ctx)
+	if err != nil {
+		return err
+	}
+	pgb.sql = query
 	return pgb.sqlScan(ctx, v)
 }
 
@@ -568,12 +613,18 @@ func (pgb *PetGroupBy) sqlQuery() *sql.Selector {
 type PetSelect struct {
 	config
 	fields []string
-	// intermediate queries.
-	sql *sql.Selector
+	// intermediate query (i.e. traversal path).
+	sql  *sql.Selector
+	path func(context.Context) (*sql.Selector, error)
 }
 
 // Scan applies the selector query and scan the result into the given value.
 func (ps *PetSelect) Scan(ctx context.Context, v interface{}) error {
+	query, err := ps.path(ctx)
+	if err != nil {
+		return err
+	}
+	ps.sql = query
 	return ps.sqlScan(ctx, v)
 }
 

examples/o2m2types/ent/user_query.go

@@ -31,8 +31,9 @@ type UserQuery struct {
 	predicates []predicate.User
 	// eager-loading edges.
 	withPets *PetQuery
-	// intermediate query.
-	sql *sql.Selector
+	// intermediate query (i.e. traversal path).
+	sql  *sql.Selector
+	path func(context.Context) (*sql.Selector, error)
 }
 
 // Where adds a new predicate for the builder.
@@ -62,12 +63,18 @@ func (uq *UserQuery) Order(o ...Order) *UserQuery {
 // QueryPets chains the current query on the pets edge.
 func (uq *UserQuery) QueryPets() *PetQuery {
 	query := &PetQuery{config: uq.config}
-	step := sqlgraph.NewStep(
-		sqlgraph.From(user.Table, user.FieldID, uq.sqlQuery()),
-		sqlgraph.To(pet.Table, pet.FieldID),
-		sqlgraph.Edge(sqlgraph.O2M, false, user.PetsTable, user.PetsColumn),
-	)
-	query.sql = sqlgraph.SetNeighbors(uq.driver.Dialect(), step)
+	query.path = func(ctx context.Context) (fromU *sql.Selector, err error) {
+		if err := uq.prepareQuery(ctx); err != nil {
+			return nil, err
+		}
+		step := sqlgraph.NewStep(
+			sqlgraph.From(user.Table, user.FieldID, uq.sqlQuery()),
+			sqlgraph.To(pet.Table, pet.FieldID),
+			sqlgraph.Edge(sqlgraph.O2M, false, user.PetsTable, user.PetsColumn),
+		)
+		fromU = sqlgraph.SetNeighbors(uq.driver.Dialect(), step)
+		return fromU, nil
+	}
 	return query
 }
 
@@ -167,6 +174,9 @@ func (uq *UserQuery) OnlyXID(ctx context.Context) int {
 
 // All executes the query and returns a list of Users.
 func (uq *UserQuery) All(ctx context.Context) ([]*User, error) {
+	if err := uq.prepareQuery(ctx); err != nil {
+		return nil, err
+	}
 	return uq.sqlAll(ctx)
 }
 
@@ -199,6 +209,9 @@ func (uq *UserQuery) IDsX(ctx context.Context) []int {
 
 // Count returns the count of the given query.
 func (uq *UserQuery) Count(ctx context.Context) (int, error) {
+	if err := uq.prepareQuery(ctx); err != nil {
+		return 0, err
+	}
 	return uq.sqlCount(ctx)
 }
 
@@ -213,6 +226,9 @@ func (uq *UserQuery) CountX(ctx context.Context) int {
 
 // Exist returns true if the query has elements in the graph.
 func (uq *UserQuery) Exist(ctx context.Context) (bool, error) {
+	if err := uq.prepareQuery(ctx); err != nil {
+		return false, err
+	}
 	return uq.sqlExist(ctx)
 }
 
@@ -236,7 +252,8 @@ func (uq *UserQuery) Clone() *UserQuery {
 		unique:     append([]string{}, uq.unique...),
 		predicates: append([]predicate.User{}, uq.predicates...),
 		// clone intermediate query.
-		sql: uq.sql.Clone(),
+		sql:  uq.sql.Clone(),
+		path: uq.path,
 	}
 }
 
@@ -269,7 +286,12 @@ func (uq *UserQuery) WithPets(opts ...func(*PetQuery)) *UserQuery {
 func (uq *UserQuery) GroupBy(field string, fields ...string) *UserGroupBy {
 	group := &UserGroupBy{config: uq.config}
 	group.fields = append([]string{field}, fields...)
-	group.sql = uq.sqlQuery()
+	group.path = func(ctx context.Context) (prev *sql.Selector, err error) {
+		if err := uq.prepareQuery(ctx); err != nil {
+			return nil, err
+		}
+		return uq.sqlQuery(), nil
+	}
 	return group
 }
 
@@ -288,10 +310,27 @@ func (uq *UserQuery) GroupBy(field string, fields ...string) *UserGroupBy {
 func (uq *UserQuery) Select(field string, fields ...string) *UserSelect {
 	selector := &UserSelect{config: uq.config}
 	selector.fields = append([]string{field}, fields...)
-	selector.sql = uq.sqlQuery()
+	selector.path = func(ctx context.Context) (prev *sql.Selector, err error) {
+		if err := uq.prepareQuery(ctx); err != nil {
+			return nil, err
+		}
+		return uq.sqlQuery(), nil
+	}
 	return selector
 }
 
+func (uq *UserQuery) prepareQuery(ctx context.Context) error {
+	if uq.path != nil {
+		prev, err := uq.path(ctx)
+		if err != nil {
+			return err
+		}
+		uq.sql = prev
+	}
+	// Privacy and query checks go here.
+	return nil
+}
+
 func (uq *UserQuery) sqlAll(ctx context.Context) ([]*User, error) {
 	var (
 		nodes       = []*User{}
@@ -431,8 +470,9 @@ type UserGroupBy struct {
 	config
 	fields []string
 	fns    []Aggregate
-	// intermediate query.
-	sql *sql.Selector
+	// intermediate query (i.e. traversal path).
+	sql  *sql.Selector
+	path func(context.Context) (*sql.Selector, error)
 }
 
 // Aggregate adds the given aggregation functions to the group-by query.
@@ -443,6 +483,11 @@ func (ugb *UserGroupBy) Aggregate(fns ...Aggregate) *UserGroupBy {
 
 // Scan applies the group-by query and scan the result into the given value.
 func (ugb *UserGroupBy) Scan(ctx context.Context, v interface{}) error {
+	query, err := ugb.path(ctx)
+	if err != nil {
+		return err
+	}
+	ugb.sql = query
 	return ugb.sqlScan(ctx, v)
 }
 
@@ -561,12 +606,18 @@ func (ugb *UserGroupBy) sqlQuery() *sql.Selector {
 type UserSelect struct {
 	config
 	fields []string
-	// intermediate queries.
-	sql *sql.Selector
+	// intermediate query (i.e. traversal path).
+	sql  *sql.Selector
+	path func(context.Context) (*sql.Selector, error)
 }
 
 // Scan applies the selector query and scan the result into the given value.
 func (us *UserSelect) Scan(ctx context.Context, v interface{}) error {
+	query, err := us.path(ctx)
+	if err != nil {
+		return err
+	}
+	us.sql = query
 	return us.sqlScan(ctx, v)
 }