Question

我正在尝试使用CodeIgnitor活动记录从三个表中获取结果。但我只是得到了与第二次加入条件匹配的记录。但我需要所有记录......

$uid   = $this->session->userdata('uid');
$codn  = ['stud.uid'=>$uid,'stud.status'=>"ACTIVE"];

$liststudent = $this->db->select('stud.id,stud.studname,stud.mobile1,stud.photo,stud.totalfees,bs.title,SUM(sp.pay_in_digit) AS paidfees')
                        ->from('students as stud')
                        ->join('batchsetting as bs', 'bs.id  = stud.bid')
                        ->join('stud_payment as sp', 'sp.sid = stud.id')
                        ->where($codn)
                        ->get();
return $liststudent->result();

这是我的查询。

概念是：我需要批量设置的批量标题，他们是谁的id = stud.bid＆＃39;。来自stud_payment的payfees和＆＃39; sid = stud.id＆＃39;。

但结果我只得到那些在stud_payment表中记录的学生记录。

Answer 1

表students没有任何名为bid的字段。所以

更改

 ->join('batchsetting as bs', 'bs.id  = stud.bid')

以

->join('batchsetting as bs', 'bs.id = stud.id')

Answer 2

尝试使用以下代码

$uid   = $this->session->userdata('uid');
$liststudent = $this->db->select('stud.id,stud.studname,stud.mobile1,stud.photo,stud.totalfees,bs.title,SUM(sp.pay_in_digit) AS paidfees')
                    ->from('students as stud')
                    ->join('batchsetting as bs', 'bs.id  = stud.id')
                    ->join('stud_payment as sp', 'sp.sid = stud.id')
                    ->where('stud.uid',$uid)
                    ->where('stud.status',"ACTIVE");
return $liststudent->result();

Answer 3

尝试在您的关节中使用左连接。代码如下：

$uid   = $this->session->userdata('uid');
$codn  = ['stud.uid'=>$uid,'stud.status'=>"ACTIVE"];

$liststudent = $this->db->select('stud.id,stud.studname,stud.mobile1,stud.photo,stud.totalfees,bs.title,SUM(sp.pay_in_digit) AS paidfees')
                        ->from('students as stud')
                        ->join('batchsetting as bs', 'bs.id  = stud.bid', 'left')
                        ->join('stud_payment as sp', 'sp.sid = stud.id', 'left')
                        ->where($codn)
                        ->get();
return $liststudent->result();

Answer 4

基本上ci bydefault考虑内部Join查询。所以你需要指定左连接

->join('stud_payment as sp', 'sp.sid = stud.id', 'left');

Answer 5

使用全外连接。

function full_outer_join() {
    $sql = 'SELECT ' . $this->blogs . '.blog_id,comment_id,blog_title,blog_content,blog_date,comment_text,comment_date
            FROM ' . $this->blogs . ' LEFT OUTER JOIN ' . $this->blog_comments . ' ON ' . $this->blog_comments . '.blog_id = ' . $this->blogs . '.blog_id
                UNION
            SELECT ' . $this->blogs . '.blog_id,comment_id,blog_title,blog_content,blog_date,comment_text,comment_date
            FROM ' . $this->blogs . ' RIGHT OUTER JOIN ' . $this->blog_comments . ' ON ' . $this->blog_comments . '.blog_id = ' . $this->blogs . '.blog_id';
    $query = $this->db->query($sql);
    return $query->result();
}

使用CodeIgniter中的join从三个表中检索数据

5 个答案: