如何加入3表

时间:2013-08-27 02:26:27

标签: php mysql sql join

我想在1页中加入3个表并显示它......

   $id = $_REQUEST["Emp_ID"];
   $test = mysql_query("select * from Employee left join department on employee.dept_id = department.dept_id 
                                               left join leave on employee.leave_id = leave_id where Emp_ID = $id");
   $row = mysql_fetch_assoc($test);

2 个答案:

答案 0 :(得分:1)

您尝试使用名称Employee加入employee。如果这是你想要的,你首先需要创建一个别名。

 select * from Employee AS employee 
 left join department on employee.dept_id = department.dept_id 
 left join leave on employee.leave_id = leave.leave_id 
 where employee.Emp_ID = $id

答案 1 :(得分:-1)

在来这里之前应该真的咨询谷歌。

SELECT t1.col, 
       t1.col,
       t2.col,
       t2.col,
       t3.col,
       t3.col
FROM    t1
    INNER JOIN t2 ON t2.foreignkey = t1.primarykey
    LEFT JOIN t3 on t3.foreignkey = t1.primarykey

如果你不能这样做..谷歌。