Mysql 一张表与多张表进行JOIN

Question

我有 4 张 table :

ADS:id、文本、数字

TABLE2:id、user_id、数字
TABLE3:id、user_id、数字
TABLE4:id、user_id、数字

user_id 不是唯一的。可以存在也可以不存在。

我想要的输出:
如果ADS表的数量等于TABLE1的数量 OR TABLE2 OR TABLE3，仅显示文本。

我已经尝试过:

SELECT ADS.text FROM ADS 
LEFT JOIN TABLE2 ON TABLE2.user_id = ? 
LEFT JOIN TABLE3 ON TABLE3.user_id = ? 
LEFT JOIN TABLE4 ON TABLE4.user_id = ? 
WHERE ADS.number = TABLE2.number OR 
ADS.number = TABLE3.number OR 
ADS.number = TABLE4.number 
GROUP BY ADS.id 

和

SELECT * FROM 
(
SELECT 
ADS.text FROM ADS 
LEFT JOIN TABLE2 ON TABLE2.user_id = ? 
LEFT JOIN TABLE3 ON TABLE3.user_id = ? 
LEFT JOIN TABLE4 ON TABLE4.user_id = ? 
WHERE ADS.number = TABLE2.number OR 
ADS.number = TABLE3.number OR 
ADS.number = TABLE4.number 

UNION ALL

SELECT 
ADS.text FROM ADS 
LEFT JOIN TABLE2 ON TABLE2.user_id = ? 
LEFT JOIN TABLE3 ON TABLE3.user_id = ? 
LEFT JOIN TABLE4 ON TABLE4.user_id = ? 
WHERE ADS.number = TABLE2.number OR 
ADS.number = TABLE3.number OR 
ADS.number = TABLE4.number 
) request 
ORDER BY ADS.id

$reponse->execute(array($_SESSION['id'],$_SESSION['id'],$_SESSION['id']));

我总是输出太多或不足......

Answer 1

这符合你的要求吗？

SELECT ADS.text
FROM ADS a
WHERE EXISTS (SELECT 1 FROM TABLE2 t WHERE t.user_id = ? AND t.number = a.number) OR
      EXISTS (SELECT 1 FROM TABLE3 t WHERE t.user_id = ? AND t.number = a.number) OR
      EXISTS (SELECT 1 FROM TABLE4 t WHERE t.user_id = ? AND t.number = a.number);