连接到多个表

Question

如何使用forign密钥ID连接到单个查询中的4个表？

我知道如何连接两个表。

$sql = "SELECT tb1.id, tb2.name FROM tblA tbl1 LEFT JOIN tblB tbl2 ON tb1.id = tbl2.studentID ORDER BY tbl1.id DESC LIMIT 20";
$statement = $con_db->prepare($sql);

Answer 1

试试这样：

select t1.ID, t2.studentID, t3.aID, t4.bID 
from  table1 as t1

left join tbl2 as t2 on t2.studentID = t1.id
left join tbl3 as t3 on t3.aID = t1.id
left join tbl4 as t4 on t4.bID = t1.id