func (db *DB) Omit(columns ...string) (tx *DB) {
	tx = db.getInstance()

	if len(columns) == 1 && strings.ContainsRune(columns[0], ',') {
		tx.Statement.Omits = strings.FieldsFunc(columns[0], utils.IsValidDBNameChar)
	} else {
		tx.Statement.Omits = columns
	}
	return
}

// Where add conditions
//

		expr := clause.Expr{SQL: "count(*)"}

		if len(tx.Statement.Selects) == 1 {
			dbName := tx.Statement.Selects[0]
			fields := strings.FieldsFunc(dbName, utils.IsValidDBNameChar)
			if len(fields) == 1 || (len(fields) == 3 && (strings.ToUpper(fields[1]) == "AS" || fields[1] == ".")) {
				if tx.Statement.Parse(tx.Statement.Model) == nil {