feat: add model embedding via embed:prefix_

internal/dbtest/db_test.go

@@ -236,6 +236,8 @@ func TestDB(t *testing.T) {
 		{testUpsert},
 		{testMultiUpdate},
 		{testTxScanAndCount},
+		{testEmbedModelValue},
+		{testEmbedModelPointer},
 	}
 
 	testEachDB(t, func(t *testing.T, dbName string, db *bun.DB) {
@@ -1029,3 +1031,59 @@ func testTxScanAndCount(t *testing.T, db *bun.DB) {
 		require.NoError(t, err)
 	}
 }
+
+func testEmbedModelValue(t *testing.T, db *bun.DB) {
+	type Embed struct {
+		Foo string
+		Bar string
+	}
+	type Model struct {
+		X Embed `bun:"embed:x_"`
+		Y Embed `bun:"embed:y_"`
+	}
+
+	ctx := context.Background()
+
+	err := db.ResetModel(ctx, (*Model)(nil))
+	require.NoError(t, err)
+
+	m1 := &Model{
+		X: Embed{Foo: "x.foo", Bar: "x.bar"},
+		Y: Embed{Foo: "y.foo", Bar: "y.bar"},
+	}
+	_, err = db.NewInsert().Model(m1).Exec(ctx)
+	require.NoError(t, err)
+
+	var m2 Model
+	err = db.NewSelect().Model(&m2).Scan(ctx)
+	require.NoError(t, err)
+	require.Equal(t, *m1, m2)
+}
+
+func testEmbedModelPointer(t *testing.T, db *bun.DB) {
+	type Embed struct {
+		Foo string
+		Bar string
+	}
+	type Model struct {
+		X *Embed `bun:"embed:x_"`
+		Y *Embed `bun:"embed:y_"`
+	}
+
+	ctx := context.Background()
+
+	err := db.ResetModel(ctx, (*Model)(nil))
+	require.NoError(t, err)
+
+	m1 := &Model{
+		X: &Embed{Foo: "x.foo", Bar: "x.bar"},
+		Y: &Embed{Foo: "y.foo", Bar: "y.bar"},
+	}
+	_, err = db.NewInsert().Model(m1).Exec(ctx)
+	require.NoError(t, err)
+
+	var m2 Model
+	err = db.NewSelect().Model(&m2).Scan(ctx)
+	require.NoError(t, err)
+	require.Equal(t, *m1, m2)
+}

schema/table.go

@@ -203,7 +203,7 @@ func (t *Table) fieldByGoName(name string) *Field {
 func (t *Table) initFields() {
 	t.Fields = make([]*Field, 0, t.Type.NumField())
 	t.FieldMap = make(map[string]*Field, t.Type.NumField())
-	t.addFields(t.Type, nil)
+	t.addFields(t.Type, "", nil)
 
 	if len(t.PKs) == 0 {
 		for _, name := range []string{"id", "uuid", "pk_" + t.ModelName} {
@@ -230,7 +230,7 @@ func (t *Table) initFields() {
 	}
 }
 
-func (t *Table) addFields(typ reflect.Type, baseIndex []int) {
+func (t *Table) addFields(typ reflect.Type, prefix string, index []int) {
 	for i := 0; i < typ.NumField(); i++ {
 		f := typ.Field(i)
 		unexported := f.PkgPath != ""
@@ -242,10 +242,6 @@ func (t *Table) addFields(typ reflect.Type, baseIndex []int) {
 			continue
 		}
 
-		// Make a copy so the slice is not shared between fields.
-		index := make([]int, len(baseIndex))
-		copy(index, baseIndex)
-
 		if f.Anonymous {
 			if f.Name == "BaseModel" && f.Type == baseModelType {
 				if len(index) == 0 {
@@ -258,7 +254,7 @@ func (t *Table) addFields(typ reflect.Type, baseIndex []int) {
 			if fieldType.Kind() != reflect.Struct {
 				continue
 			}
-			t.addFields(fieldType, append(index, f.Index...))
+			t.addFields(fieldType, "", withIndex(index, f.Index))
 
 			tag := tagparser.Parse(f.Tag.Get("bun"))
 			if _, inherit := tag.Options["inherit"]; inherit {
@@ -274,7 +270,7 @@ func (t *Table) addFields(typ reflect.Type, baseIndex []int) {
 			continue
 		}
 
-		if field := t.newField(f, index); field != nil {
+		if field := t.newField(f, prefix, index); field != nil {
 			t.addField(field)
 		}
 	}
@@ -315,10 +311,20 @@ func (t *Table) processBaseModelField(f reflect.StructField) {
 }
 
 //nolint
-func (t *Table) newField(f reflect.StructField, index []int) *Field {
-	sqlName := internal.Underscore(f.Name)
+func (t *Table) newField(f reflect.StructField, prefix string, index []int) *Field {
 	tag := tagparser.Parse(f.Tag.Get("bun"))
 
+	if prefix, ok := tag.Option("embed"); ok {
+		fieldType := indirectType(f.Type)
+		if fieldType.Kind() != reflect.Struct {
+			panic(fmt.Errorf("bun: embed %s.%s: got %s, wanted reflect.Struct",
+				t.TypeName, f.Name, fieldType.Kind()))
+		}
+		t.addFields(fieldType, prefix, withIndex(index, f.Index))
+		return nil
+	}
+
+	sqlName := internal.Underscore(f.Name)
 	if tag.Name != "" && tag.Name != sqlName {
 		if isKnownFieldOption(tag.Name) {
 			internal.Warn.Printf(
@@ -328,18 +334,18 @@ func (t *Table) newField(f reflect.StructField, index []int) *Field {
 		}
 		sqlName = tag.Name
 	}
-
 	if s, ok := tag.Option("column"); ok {
 		sqlName = s
 	}
+	sqlName = prefix + sqlName
 
 	for name := range tag.Options {
 		if !isKnownFieldOption(name) {
 			internal.Warn.Printf("%s.%s has unknown tag option: %q", t.TypeName, f.Name, name)
 		}
 	}
 
-	index = append(index, f.Index...)
+	index = withIndex(index, f.Index)
 	if field := t.fieldWithLock(sqlName); field != nil {
 		if indexEqual(field.Index, index) {
 			return field
@@ -795,7 +801,7 @@ func (t *Table) inlineFields(field *Field, seen map[reflect.Type]struct{}) {
 		f.GoName = field.GoName + "_" + f.GoName
 		f.Name = field.Name + "__" + f.Name
 		f.SQLName = t.quoteIdent(f.Name)
-		f.Index = appendNew(field.Index, f.Index...)
+		f.Index = withIndex(field.Index, f.Index)
 
 		t.fieldsMapMu.Lock()
 		if _, ok := t.FieldMap[f.Name]; !ok {
@@ -853,13 +859,6 @@ func (t *Table) quoteIdent(s string) Safe {
 	return Safe(NewFormatter(t.dialect).AppendIdent(nil, s))
 }
 
-func appendNew(dst []int, src ...int) []int {
-	cp := make([]int, len(dst)+len(src))
-	copy(cp, dst)
-	copy(cp[len(dst):], src)
-	return cp
-}
-
 func isKnownTableOption(name string) bool {
 	switch name {
 	case "table", "alias", "select":
@@ -991,3 +990,10 @@ func softDeleteFieldUpdaterFallback(field *Field) func(fv reflect.Value, tm time
 		return field.ScanWithCheck(fv, tm)
 	}
 }
+
+func withIndex(a, b []int) []int {
+	dest := make([]int, 0, len(a)+len(b))
+	dest = append(dest, a...)
+	dest = append(dest, b...)
+	return dest
+}