我在codeigniter中遇到以下错误

错误号：1064

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE `appID` = 'buttn_default'' at line 2

SELECT `responseURL` WHERE `appID` = 'buttn_default'

这是我用于从数据库获取数据的模态函数

function get_response_url($appID, $merchant_id)
    {
        $this->db->select('responseURL');
        $this->db->from('response_urls');
        $this->db->where('appID',$appID);
        //$this->db->or_where('merchant_id',$merchant_id);
        $query = $this->db->get();
        if($query->num_rows() == 1)
        {
            foreach($query->result() as $row)
            return $row->responseURL;
        }
    else
        {
            $appID='buttn_default';
            $this->db->select('responseURL');
            $this->db->where('appID',$appID);
            $query = $this->db->get();
            if($query->num_rows() == 1)
            foreach($query->result() as $row)
            return $row->responseURL;
        }

    }

为什么不起作用,为什么我会得到这个错误.

解决方法:

您的mysql错误显示没有from子句,而您的else部分也与活动记录的from()函数一起丢失

else
    {
        $appID='buttn_default';
        $this->db->select('responseURL');
        $this->db->from('table_name_here');  <------
        $this->db->where('appID',$appID);
        $query = $this->db->get();
        if($query->num_rows() == 1)
        foreach($query->result() as $row)
        return $row->responseURL;
    }