MySQL完全外部连接帮助

我知道MySQL完全外部连接是语法错误。 我在mysql5中有一个完整的外部连接，我想创建一个类似的查询。

---

我该怎么办？

使用左连接和右连接的并集。问题出在哪里？您好，欢迎使用SO。不幸的是，你第一次提出问题的尝试显然是有缺陷的。建议阅读指南并重新修订/开始。

You can emulate FULL OUTER JOIN using UNION (from MySQL 4.0.0 on):

with two tables t1, t2:

SELECT * FROM t1
LEFT JOIN t2 ON t1.id = t2.id
UNION
SELECT * FROM t1
RIGHT JOIN t2 ON t1.id = t2.id

with three tables t1, t2, t3:

SELECT * FROM t1
LEFT JOIN t2 ON t1.id = t2.id
LEFT JOIN t3 ON t2.id = t3.id
UNION
SELECT * FROM t1
RIGHT JOIN t2 ON t1.id = t2.id
LEFT JOIN t3 ON t2.id = t3.id
UNION
SELECT * FROM t1
RIGHT JOIN t2 ON t1.id = t2.id
RIGHT JOIN t3 ON t2.id = t3.id