// returned to the connection pool.
func (db *DB) Connection(fc func(tx *DB) error) (err error) {
	if db.Error != nil {
		return db.Error
	}

	tx := db.getInstance()
	sqlDB, err := tx.DB()
	if err != nil {
		return
	}

	conn, err := sqlDB.Conn(tx.Statement.Context)
	if err != nil {
		return
	}

	defer conn.Close()
	tx.Statement.ConnPool = conn
	return fc(tx)
}

			primaryKeys: toColumns(field.TagSettings["REFERENCES"]),
		}
	)

	cacheStore := schema.cacheStore

	if relation.FieldSchema, err = getOrParse(fieldValue, cacheStore, schema.namer); err != nil {
		schema.err = err
		return nil
	}

	if hasPolymorphicRelation(field.TagSettings) {
		schema.buildPolymorphicRelation(relation, field)
	} else if many2many := field.TagSettings["MANY2MANY"]; many2many != "" {

	CreatedAt  time.Time
	UpdatedAt  time.Time
}

func TestNonStdPrimaryKeyAndDefaultValues(t *testing.T) {
	DB.Migrator().DropTable(&Animal{})
	if err := DB.AutoMigrate(&Animal{}); err != nil {
		t.Fatalf("no error should happen when migrate but got %v", err)
	}

	animal := Animal{Name: "Ferdinand"}
	DB.Save(&animal)
	updatedAt1 := animal.UpdatedAt

	DB.Save(&animal).Update("name", "Francis")

	user3 := User{Name: "RowUser3", Age: 20}
	DB.Save(&user1).Save(&user2).Save(&user3)

	row := DB.Table("users").Where("name = ?", user2.Name).Select("age").Row()

	var age int64
	if err := row.Scan(&age); err != nil {
		t.Fatalf("Failed to scan age, got %v", err)
	}

	if age != 10 {
		t.Errorf("Scan with Row, age expects: %v, got %v", user2.Age, age)
	}

	table := "gorm.users"
	if DB.Dialector.Name() != "mysql" || isTiDB() {

)

func Query(db *gorm.DB) {
	if db.Error == nil {
		BuildQuerySQL(db)

		if !db.DryRun && db.Error == nil {
			rows, err := db.Statement.ConnPool.QueryContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
			if err != nil {
				db.AddError(err)
				return
			}
			defer func() {
				db.AddError(rows.Close())
			}()
			gorm.Scan(rows, db, 0)
		}
	}
}

		t.Fatalf("Error happened when delete pet, got %v", err)
	}
	AssertAssociationCount(t, user2, "Pets", 1, "after delete non-existing data")

	if err := DB.Model(&user2).Association("Pets").Delete(&pet2); err != nil {
		t.Fatalf("Error happened when delete Pets, got %v", err)
	}
	AssertAssociationCount(t, user2, "Pets", 0, "after delete")

	// Prepare Data for Clear

			tx.Rollback()
		}
	}()
	if err := tx.Error; err != nil {
		t.Errorf("Failed to start transaction, got error %v\n", err)
	}

	if err := tx.Where("name=?", "zzjin").Delete(&User{}).Error; err != nil {
		tx.Rollback()
		t.Errorf("Failed to run one transaction, got error %v\n", err)
	}

	if err := tx.Create(&User{Name: "zzjin"}).Error; err != nil {
		tx.Rollback()

	// Delete
	if err := DB.Model(&user2).Association("Account").Delete(&Account{}); err != nil {
		t.Fatalf("Error happened when delete account, got %v", err)
	}
	AssertAssociationCount(t, user2, "Account", 1, "after delete non-existing data")

	if err := DB.Model(&user2).Association("Account").Delete(&account2); err != nil {
		t.Fatalf("Error happened when delete Account, got %v", err)
	}

	type user struct {
		ID    int `gorm:"primaryKey"`
		Name  string
		Email string `gorm:"default:(-)"`
		Age   int    `gorm:"default:(-)"`
	}

	s, err := schema.Parse(&user{}, schemaCache, schema.NamingStrategy{})
	if err != nil {
		t.Errorf("parse schema error: %v, is not expected", err)
		return
	}
	dest := []*user{
		{
			ID:    1,
			Name:  "alice",
			Email: "email",
			Age:   18,
		},
		{
			ID:    2,

			// clear old data
			if clear && len(values) == 0 {
				for i := 0; i < reflectValue.Len(); i++ {
					if err := association.Relationship.Field.Set(association.DB.Statement.Context, reflectValue.Index(i), reflect.New(association.Relationship.Field.IndirectFieldType).Interface()); err != nil {
						association.Error = err
						break
					}

					if association.Relationship.JoinTable == nil {