本文介绍了MySQL 完全加入?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着跟版网的小编来一起学习吧！
问题描述
限时送ChatGPT账号..
以下是我的查询，我想要如下所示的结果.我怎样才能在 mysql 中做到这一点?
Following are my query and I want the result as given below. How can I do this in mysql ?
SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo
FROM Persons
FULL JOIN Orders
ON Persons.P_Id=Orders.P_Id
ORDER BY Persons.LastName
结果集需要看起来像这样:
The result-set need to look like this:
LastName FirstName OrderNo
Hansen Ola 22456
Hansen Ola 24562
Pettersen Kari 77895
Pettersen Kari 44678
Svendson Tove
34764
推荐答案
MySQL 缺乏对 FULL OUTER JOIN 的支持.
MySQL lacks support for FULL OUTER JOIN.
因此，如果您想在 MySQL 上模拟完整连接，请查看 这里 .
So if you want to emulate a Full join on MySQL take a look here .
通常建议的解决方法如下:
A commonly suggested workaround looks like this:
SELECT t_13.value AS val13, t_17.value AS val17
FROM t_13
LEFT JOIN
t_17
ON t_13.value = t_17.value
UNION ALL
SELECT t_13.value AS val13, t_17.value AS val17
FROM t_13
RIGHT JOIN
t_17
ON t_13.value = t_17.value
WHERE t_13.value IS NULL
ORDER BY
COALESCE(val13, val17)
LIMIT 30
这篇关于MySQL 完全加入?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！
本站部分内容来源互联网,如果有图片或者内容侵犯了您的权益，请联系我们，我们会在确认后第一时间进行删除！