t.Fatalf("errors happened when create: %v", err)
	}

	user.Languages = []Language{{Code: "zh-CN", Name: "Chinese"}, {Code: "en", Name: "English"}}
	for _, lang := range user.Languages {
		DB.Create(&lang)
	}
	user.Friends = []*User{{Name: "friend-1"}, {Name: "friend-2"}}

	if err := DB.Save(&user).Error; err != nil {
		t.Fatalf("errors happened when update: %v", err)
	}

	var user2 User

func TestSaveWithPrimaryValue(t *testing.T) {
	lang := Language{Code: "save", Name: "save"}
	if result := DB.Save(&lang); result.RowsAffected != 1 {
		t.Errorf("should create language, rows affected: %v", result.RowsAffected)
	}

	var result Language
	DB.First(&result, "code = ?", "save")
	AssertEqual(t, result, lang)

	lang.Name = "save name2"
	if result := DB.Save(&lang); result.RowsAffected != 1 {

	}

	for _, lang := range langs {
		var result Language
		if err := DB.First(&result, "code = ?", lang.Code).Error; err != nil {
			t.Errorf("Failed to query lang, got error %v", err)
		} else {
			AssertEqual(t, result, lang)
		}
	}

	for idx, lang := range langs {
		lang.Name += "_new"
		langs[idx] = lang
	}

	if err := DB.Save(&langs).Error; err != nil {