"Syntax error or access violation" 多次尝试加入 table 列时出错

Question

我想加入名为 members、students 和 baseinfos 的 3 个表。

并且 baseinfos 将一些 id 保存为 bas_id 并且它的名称存储在 bas_value:

这是我的代码：

$records = DB::table('members')
            ->where('mys_olp_id',4)
            ->join('students', 'members.mbr_usr_id', '=', 'students.std_mbr_id')
            ->join('baseinfos as gender', 'members.mbr_gender_id', '=', 'gender.bas_id as gvalue')
            ->join('baseinfos as degree', 'students.std_degree_id', '=', 'degree.bas_id as dvalue')
            ->select('gender.gvalue', 'degree.dvalue')
            ->get()->toArray();

但这是错误的，并向我显示了这个错误：

SQLSTATE[42000]: Syntax error or access violation: 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 'as `gvalue` inner join `baseinfos` as `degree`

请注意，我不能这样说：

$records = DB::table('members')
            ->where('my_students.mys_olp_id',4)
            ->join('students', 'members.mbr_usr_id', '=', 'students.std_mbr_id')
            ->join('baseinfos as degree', 'students.std_degree_id', '=', 'degree.bas_id')
            ->join('baseinfos as gender', 'members.mbr_gender_id', '=', 'gender.bas_id')
            ->select('gender.bas_value', 'degree.bas_value')
            ->get()->toArray();

因为degree.bas_value会覆盖gender.bas_value！

那么如何正确连接这 3 个表？

Answer 1

您在 join 中的别名格式不正确。我认为你可以通过这种方式实现这一目标-

$records = DB::table('members')
            ->join('students', 'students.std_mbr_id', '=', 'members.mbr_usr_id')
            ->join('baseinfos as gender','gender.bas_id', '=', 'members.mbr_gender_id')
            ->join('baseinfos as degree','degree.bas_id' , '=', 'students.std_degree_id')
            ->where('mys_olp_id',4)
            ->select('gender.bas_id as gvalue', 'degree.bas_id as dvalue')
            ->get();

"Syntax error or access violation" 多次尝试加入 table 列时出错

"Syntax error or access violation" error while trying to join a table column multiple times

php

join

laravel

laravel-5.8