如何加入3表

Question

我想加入3表1頁並顯示它...

$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); 

Answer 1

您嘗試使用名稱employee加入Employee。如果這是你打算首先需要創建一個別名。

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 

Answer 2

在來這裏之前，應該真的諮詢谷歌。

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 

如果你不能遵循這個..谷歌。