Mysql多個左邊的連接在同一張桌子上

Question

我有一個引用另一個表的ID的兩個字段的表。我需要從另一個表中爲這兩個字段取名。

例如。

 
Table1 
worker1 = 2 (2 is key to other table) 
worker2 = 4
 

Table2 
ID NAME 
1 Bill 
2 Fred 
3 John 
4 Paul 

我需要得到$ worker1name = Fred和$ worker2name = Paul。

所以我會說是這樣的：

SELECT xxx, NAME?, NAME? FROM Table1 
LEFT JOIN Table2 AS p1 ON Table1.worker1 = Table2.ID 
LEFT JOIN Table2 AS p2 ON Table1.worker2 = Table2.ID 
WHERE ... 

$table = mysql_query(...); 
$rec = mysql_fetch_assoc($table); 
$worker1name = $rec['???']; 
$worker2name = $rec['???']; 

什麼我提到的最後兩個語句插入拿到兩個名字。或者更確切地說，我必須添加到SELECT以指定我希望表2中名稱字段的兩個不同版本被調用的內容？

Answer 1

你應該別名領域也是這樣：

SELECT 
    xxx, 
    p1.NAME as p1name, 
    p2.NAME as p2name 
FROM Table1 
LEFT JOIN Table2 AS p1 ON Table1.worker1 = p1.ID 
LEFT JOIN Table2 AS p2 ON Table1.worker2 = p2.ID 
WHERE ... 

Answer 2

SELECT xxx, p1.NAME AS p1Name, p2.NAME AS p2Name FROM Table1 


$worker1name = $rec['p1Name']; 
$worker2name = $rec['p2Name'];