mysql-联接查询可以对一个查询执行相同的任务吗

它可以合并到一个查询中吗？

我不确定我是否完全理解你的问题，但是如果

C1

，

C2

，…，

Cn

都是“并行”表，那么也许联合会起作用：

Table A
Table B
Tabls C1, C2 .... Cn : title field

relationship C INNER JOIN B LEFT JOIN A

query 
SELECT C1.title FORM C1 
INNER JOIN B on C1.c_id = B.c_id
LEFT JOIN A on B.b_id = A.b_id

---

在我看来，这也是一个问题！我会试试的，也许这就是我需要的

SELECT C1.title AS title FROM C1 INNER JOIN B on C1.c_id = B.c_id LEFT JOIN A on B.b_id = A.b_id
UNION ALL
SELECT C2.title AS title FROM C2 INNER JOIN B on C2.c_id = B.c_id LEFT JOIN A on B.b_id = A.b_id
UNION ALL
...
UNION ALL
SELECT Cn.title AS title FROM Cn INNER JOIN B on Cn.c_id = B.c_id LEFT JOIN A on B.b_id = A.b_id