Driver_Database_Driver_MySQLI_Transaction::_set_save_point

设置子事务的保存点，用于支持子事务的回滚

Boolean Driver_Database_Driver_MySQLI_Transaction::_set_save_point( )

返回值

Boolean true:成功；false:失败

File: ./drivers/database/mysqli/transaction.class.php

protected function _set_save_point()
{
    if (!$this->is_root())
    {
        //只有子事务才需要保存点
        if ( true === $this->_query("SAVEPOINT {$this->id};") )
        {
            return true;
        }
    }

    return false;
}