From 446ce99a42ffe050b77bdd761271f97dd1e2b554 Mon Sep 17 00:00:00 2001
From: Jinzhu <wosmvp@gmail.com>
Date: Mon, 5 Sep 2016 22:26:57 +0800
Subject: [PATCH] Support set prefix for embedded struct

---
 embedded_struct_test.go | 18 ++++++++++++++++++
 migration_test.go       |  1 -
 model_struct.go         |  3 +++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/embedded_struct_test.go b/embedded_struct_test.go
index 7be75d99..89938bc6 100644
--- a/embedded_struct_test.go
+++ b/embedded_struct_test.go
@@ -8,16 +8,34 @@ type BasePost struct {
 	URL   string
 }
 
+type Author struct {
+	Name  string
+	Email string
+}
+
 type HNPost struct {
 	BasePost
+	Author  `gorm:"embedded_prefix:user_"` // Embedded struct
 	Upvotes int32
 }
 
 type EngadgetPost struct {
 	BasePost BasePost `gorm:"embedded"`
+	Author   Author   `gorm:"embedded;embedded_prefix:author_"` // Embedded struct
 	ImageUrl string
 }
 
+func TestPrefixColumnNameForEmbeddedStruct(t *testing.T) {
+	dialect := DB.NewScope(&EngadgetPost{}).Dialect()
+	if !dialect.HasColumn(DB.NewScope(&EngadgetPost{}).TableName(), "author_name") || !dialect.HasColumn(DB.NewScope(&EngadgetPost{}).TableName(), "author_email") {
+		t.Errorf("should has prefix for embedded columns")
+	}
+
+	if !dialect.HasColumn(DB.NewScope(&HNPost{}).TableName(), "user_name") || !dialect.HasColumn(DB.NewScope(&HNPost{}).TableName(), "user_email") {
+		t.Errorf("should has prefix for embedded columns")
+	}
+}
+
 func TestSaveAndQueryEmbeddedStruct(t *testing.T) {
 	DB.Save(&HNPost{BasePost: BasePost{Title: "news"}})
 	DB.Save(&HNPost{BasePost: BasePost{Title: "hn_news"}})
diff --git a/migration_test.go b/migration_test.go
index 30085263..08633283 100644
--- a/migration_test.go
+++ b/migration_test.go
@@ -256,7 +256,6 @@ func runMigration() {
 	for _, value := range values {
 		DB.DropTable(value)
 	}
-
 	if err := DB.AutoMigrate(values...).Error; err != nil {
 		panic(fmt.Sprintf("No error should happen when create table, but got %+v", err))
 	}
diff --git a/model_struct.go b/model_struct.go
index d9e84c3c..8179a1f3 100644
--- a/model_struct.go
+++ b/model_struct.go
@@ -203,6 +203,9 @@ func (scope *Scope) GetModelStruct() *ModelStruct {
 					for _, subField := range scope.New(fieldValue).GetStructFields() {
 						subField = subField.clone()
 						subField.Names = append([]string{fieldStruct.Name}, subField.Names...)
+						if prefix, ok := field.TagSettings["EMBEDDED_PREFIX"]; ok {
+							subField.DBName = prefix + subField.DBName
+						}
 						if subField.IsPrimaryKey {
 							modelStruct.PrimaryFields = append(modelStruct.PrimaryFields, subField)
 						}