async def get_db():
    db = DBSession()
    try:
        yield db
    finally:

func (target *PostgreSQLTarget) initPostgreSQL() error {
	args := target.args

	db, err := sql.Open("postgres", target.connString)
	if err != nil {
		return err
	}
	target.db = db

	if args.MaxOpenConnections > 0 {
		// Set the maximum connections limit
		target.db.SetMaxOpenConns(args.MaxOpenConnections)
	}

	err = target.db.Ping()
	if err != nil {
		if !xnet.IsConnRefusedErr(err) && !xnet.IsConnResetErr(err) {

	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")

	}

	DB.Model(&person).Association("Addresses").Clear()

	if DB.Model(&person).Association("Addresses").Count() != 0 {
		t.Fatalf("Should deleted all addresses")
	}

	if DB.Unscoped().Model(&person).Association("Addresses").Count() != 2 {
		t.Fatalf("Should found soft deleted addresses with unscoped")
	}

	DB.Unscoped().Model(&person).Association("Addresses").Clear()

	CreateClauses        []string
	QueryClauses         []string
	UpdateClauses        []string
	DeleteClauses        []string
}

func RegisterDefaultCallbacks(db *gorm.DB, config *Config) {
	enableTransaction := func(db *gorm.DB) bool {
		return !db.SkipDefaultTransaction
	}

	if len(config.CreateClauses) == 0 {
		config.CreateClauses = createClauses
	}
	if len(config.QueryClauses) == 0 {

			return db.Table("toys").Select("name")
		}).Count(&count12).Error; err == nil {
		t.Errorf("error should raise when using preload without schema")
	}

	var count13 int64
	if err := DB.Model(User{}).
		Where("name in ?", []string{user1.Name, user2.Name, user3.Name}).
		Preload("Toys", func(db *gorm.DB) *gorm.DB {
			return db.Table("toys").Select("name")
		}).Count(&count13).Error; err != nil {

		ID   ID
		Name string
	}

	DB.Migrator().DropTable(&CustomizedTypePrimaryKey{})
	if err := DB.AutoMigrate(&CustomizedTypePrimaryKey{}); err != nil {
		t.Fatalf("failed to migrate, got error %v", err)
	}

	p1 := CustomizedTypePrimaryKey{Name: "p1"}
	p2 := CustomizedTypePrimaryKey{Name: "p2"}
	p3 := CustomizedTypePrimaryKey{Name: "p3"}
	DB.Create(&p1)
	DB.Create(&p2)
	DB.Create(&p3)

	}}

	for idx, result := range results {
		t.Run(fmt.Sprintf("case #%v", idx), func(t *testing.T) {
			user, _ := schema.Parse(&tests.User{}, &sync.Map{}, db.NamingStrategy)
			stmt := &gorm.Statement{DB: db, Table: user.Table, Schema: user, Clauses: map[string]clause.Clause{}}
			clause.Expr{SQL: result.SQL, Vars: result.Vars}.Build(stmt)
			if stmt.SQL.String() != result.Result {

		*Author `gorm:"EmbeddedPrefix:user_"` // Embedded struct
	}

	DB.Migrator().DropTable(&HNPost{})
	if err := DB.Migrator().AutoMigrate(&HNPost{}); err != nil {
		t.Fatalf("failed to auto migrate, got error: %v", err)
	}

	DB.Create(&HNPost{BasePost: &BasePost{Title: "embedded_pointer_type"}})

	var hnPost HNPost
	if err := DB.First(&hnPost, "title = ?", "embedded_pointer_type").Error; err != nil {

	if err := DB.Create(&user).Error; err != nil {
		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 {