entc/gen: add Aggregate to <T>Select and <T>Query

examples/start/ent/car_query.go

@@ -336,6 +336,11 @@ func (cq *CarQuery) Select(fields ...string) *CarSelect {
 	return selbuild
 }
 
+// Aggregate returns a CarSelect configured with the given aggregations.
+func (cq *CarQuery) Aggregate(fns ...AggregateFunc) *CarSelect {
+	return cq.Select().Aggregate(fns...)
+}
+
 func (cq *CarQuery) prepareQuery(ctx context.Context) error {
 	for _, f := range cq.fields {
 		if !car.ValidColumn(f) {
@@ -576,8 +581,6 @@ func (cgb *CarGroupBy) sqlQuery() *sql.Selector {
 	for _, fn := range cgb.fns {
 		aggregation = append(aggregation, fn(selector))
 	}
-	// If no columns were selected in a custom aggregation function, the default
-	// selection is the fields used for "group-by", and the aggregation functions.
 	if len(selector.SelectedColumns()) == 0 {
 		columns := make([]string, 0, len(cgb.fields)+len(cgb.fns))
 		for _, f := range cgb.fields {
@@ -597,6 +600,12 @@ type CarSelect struct {
 	sql *sql.Selector
 }
 
+// Aggregate adds the given aggregation functions to the selector query.
+func (cs *CarSelect) Aggregate(fns ...AggregateFunc) *CarSelect {
+	cs.fns = append(cs.fns, fns...)
+	return cs
+}
+
 // Scan applies the selector query and scans the result into the given value.
 func (cs *CarSelect) Scan(ctx context.Context, v any) error {
 	if err := cs.prepareQuery(ctx); err != nil {
@@ -607,6 +616,16 @@ func (cs *CarSelect) Scan(ctx context.Context, v any) error {
 }
 
 func (cs *CarSelect) sqlScan(ctx context.Context, v any) error {
+	aggregation := make([]string, 0, len(cs.fns))
+	for _, fn := range cs.fns {
+		aggregation = append(aggregation, fn(cs.sql))
+	}
+	switch n := len(*cs.selector.flds); {
+	case n == 0 && len(aggregation) > 0:
+		cs.sql.Select(aggregation...)
+	case n != 0 && len(aggregation) > 0:
+		cs.sql.AppendSelect(aggregation...)
+	}
 	rows := &sql.Rows{}
 	query, args := cs.sql.Query()
 	if err := cs.driver.Query(ctx, query, args, rows); err != nil {

examples/start/ent/ent.go

@@ -271,6 +271,7 @@ func IsConstraintError(err error) bool {
 type selector struct {
 	label string
 	flds  *[]string
+	fns   []AggregateFunc
 	scan  func(context.Context, any) error
 }
 

examples/start/ent/group_query.go

@@ -336,6 +336,11 @@ func (gq *GroupQuery) Select(fields ...string) *GroupSelect {
 	return selbuild
 }
 
+// Aggregate returns a GroupSelect configured with the given aggregations.
+func (gq *GroupQuery) Aggregate(fns ...AggregateFunc) *GroupSelect {
+	return gq.Select().Aggregate(fns...)
+}
+
 func (gq *GroupQuery) prepareQuery(ctx context.Context) error {
 	for _, f := range gq.fields {
 		if !group.ValidColumn(f) {
@@ -599,8 +604,6 @@ func (ggb *GroupGroupBy) sqlQuery() *sql.Selector {
 	for _, fn := range ggb.fns {
 		aggregation = append(aggregation, fn(selector))
 	}
-	// If no columns were selected in a custom aggregation function, the default
-	// selection is the fields used for "group-by", and the aggregation functions.
 	if len(selector.SelectedColumns()) == 0 {
 		columns := make([]string, 0, len(ggb.fields)+len(ggb.fns))
 		for _, f := range ggb.fields {
@@ -620,6 +623,12 @@ type GroupSelect struct {
 	sql *sql.Selector
 }
 
+// Aggregate adds the given aggregation functions to the selector query.
+func (gs *GroupSelect) Aggregate(fns ...AggregateFunc) *GroupSelect {
+	gs.fns = append(gs.fns, fns...)
+	return gs
+}
+
 // Scan applies the selector query and scans the result into the given value.
 func (gs *GroupSelect) Scan(ctx context.Context, v any) error {
 	if err := gs.prepareQuery(ctx); err != nil {
@@ -630,6 +639,16 @@ func (gs *GroupSelect) Scan(ctx context.Context, v any) error {
 }
 
 func (gs *GroupSelect) sqlScan(ctx context.Context, v any) error {
+	aggregation := make([]string, 0, len(gs.fns))
+	for _, fn := range gs.fns {
+		aggregation = append(aggregation, fn(gs.sql))
+	}
+	switch n := len(*gs.selector.flds); {
+	case n == 0 && len(aggregation) > 0:
+		gs.sql.Select(aggregation...)
+	case n != 0 && len(aggregation) > 0:
+		gs.sql.AppendSelect(aggregation...)
+	}
 	rows := &sql.Rows{}
 	query, args := gs.sql.Query()
 	if err := gs.driver.Query(ctx, query, args, rows); err != nil {

examples/start/ent/user_query.go

@@ -372,6 +372,11 @@ func (uq *UserQuery) Select(fields ...string) *UserSelect {
 	return selbuild
 }
 
+// Aggregate returns a UserSelect configured with the given aggregations.
+func (uq *UserQuery) Aggregate(fns ...AggregateFunc) *UserSelect {
+	return uq.Select().Aggregate(fns...)
+}
+
 func (uq *UserQuery) prepareQuery(ctx context.Context) error {
 	for _, f := range uq.fields {
 		if !user.ValidColumn(f) {
@@ -674,8 +679,6 @@ func (ugb *UserGroupBy) sqlQuery() *sql.Selector {
 	for _, fn := range ugb.fns {
 		aggregation = append(aggregation, fn(selector))
 	}
-	// If no columns were selected in a custom aggregation function, the default
-	// selection is the fields used for "group-by", and the aggregation functions.
 	if len(selector.SelectedColumns()) == 0 {
 		columns := make([]string, 0, len(ugb.fields)+len(ugb.fns))
 		for _, f := range ugb.fields {
@@ -695,6 +698,12 @@ type UserSelect struct {
 	sql *sql.Selector
 }
 
+// Aggregate adds the given aggregation functions to the selector query.
+func (us *UserSelect) Aggregate(fns ...AggregateFunc) *UserSelect {
+	us.fns = append(us.fns, fns...)
+	return us
+}
+
 // Scan applies the selector query and scans the result into the given value.
 func (us *UserSelect) Scan(ctx context.Context, v any) error {
 	if err := us.prepareQuery(ctx); err != nil {
@@ -705,6 +714,16 @@ func (us *UserSelect) Scan(ctx context.Context, v any) error {
 }
 
 func (us *UserSelect) sqlScan(ctx context.Context, v any) error {
+	aggregation := make([]string, 0, len(us.fns))
+	for _, fn := range us.fns {
+		aggregation = append(aggregation, fn(us.sql))
+	}
+	switch n := len(*us.selector.flds); {
+	case n == 0 && len(aggregation) > 0:
+		us.sql.Select(aggregation...)
+	case n != 0 && len(aggregation) > 0:
+		us.sql.AppendSelect(aggregation...)
+	}
 	rows := &sql.Rows{}
 	query, args := us.sql.Query()
 	if err := us.driver.Query(ctx, query, args, rows); err != nil {