php - CodeIgniter 有时会收到消息查询错误

Question

虽然这种情况很少发生，但有时我的项目会在我的查询中显示错误消息。

我认为这不是因为我的查询而发生的。

关于为什么会发生这种情况有什么建议吗？

这是我的查询示例。

select * from (
        select rlog.id_issue, created.LogUser as create_by, created.LogTime as create_time,r_change.change_by,rlog.tglupt,
        r_aprove.date1 as aproved_date,issue_type,nama_app,status,kondisi,logAct, r_issue.keterangan, logket, param
        from (select id_issue, logAct, max(logtime) as tglupt,param, logket from r_log group by id_issue, logAct, logket,param) rlog
        inner join (select Id_issue, LogUser, LogTime from r_log where LogAct like 'add%' ) created on rlog.id_issue = created.id_issue
        left join r_change on rlog.id_issue = r_change.id_issue
        left join r_aprove on r_change.id_change = r_aprove.id_change
        left join r_issue on rlog.id_issue = r_issue.id_issue
        inner join r_app_det on r_issue.id_app = r_app_det.id_app
        )z where issue_type is not null
        and id_issue = ".$id."
        order by tglupt, case when logAct = 'Add' then '1' else logact end asc

这是我的 $query =$this->db->query("SELECT * FROM mUser WHERE username='".$uname."'"); 的数据:

-----------------------------------------
  username   |     name        |  role
-----------------------------------------
    ADR      |     andry       |    2
    AND      |     Andrew      |    4
 ------------------------------------------ 

-对不起，如果我的英语不好。

Answer 1

对于一些 $uname 你没有得到任何结果。因此，在转换为 row() 之前，您应该检查查询是否返回结果。像这样

$query =$this->db->query("SELECT * FROM mUser WHERE username='".$uname."'"); 
if($query->num_rows() == 1){
    $query->row();
}else{
 //....
}