Question

我有一个包含INNER JOIN的SELECT查询。我正在寻找一种方法来创建相同的查询，但没有任何类型的JOIN。这是我当前的查询;

SELECT loan.duedate, loan.no, student.name FROM loan INNER JOIN student ON loan.no = student.no ORDER BY loan.duedate DESC LIMIT 1

这是可能的吗？我将如何创建它？

Answer 1

忽略＆＃39;为什么＆＃39;如果JOIN是1：1，您可以使用子选择而不是JOIN;

SELECT 
    loan.duedate, 
    loan.no, 
    (SELECT student.name FROM student WHERE student.no = loan.no) AS name 
FROM 
    loan
ORDER BY 
    loan.duedate DESC 
LIMIT 1

Answer 2

简单到足以转换但内部连接更有意义。

SELECT loan.duedate, loan.no, student.name 
FROM loan l,
student s 
Where l.no = s.no
ORDER BY l.duedate DESC 
LIMIT 1

从SELECT查询中删除JOIN

2 个答案: