stmt := gorm.Statement{DB: DB}
		stmt.Parse(&Blog{})
		stmt.Schema.LookUpField("ID").Unique = true
		stmt.Parse(&Tag{})
		stmt.Schema.LookUpField("ID").Unique = true
		// postgers only allow unique constraint matching given keys
	}

	DB.Migrator().DropTable(&Blog{}, &Tag{}, "blog_tags", "locale_blog_tags", "shared_blog_tags")
	if err := DB.AutoMigrate(&Blog{}, &Tag{}); err != nil {

	// IgnoreRelationshipsWhenMigrating
	IgnoreRelationshipsWhenMigrating bool
	// DisableNestedTransaction disable nested transaction
	DisableNestedTransaction bool
	// AllowGlobalUpdate allow global update
	AllowGlobalUpdate bool
	// QueryFields executes the SQL query with all fields of the table
	QueryFields bool
	// CreateBatchSize default create batch size
	CreateBatchSize int