mysql查询,更好的方法来写这个？

Question

编辑 我明白桌子是一团糟.我接管了这个项目并重写了PHP并对数据库进行了重大更改.我不是问我应该如何布局数据库.我需要快速,临时修复,我正在寻找一种更好的方式来编写下面的查询. 结束编辑

嗨,您好!

所以我有这个查询(下面)这个没有完成并且变得越来越长.我想知道是否有办法缩短它,或者是否有更好的方法来解决它...？

SELECT user.*,
cat1id.CategoryName as cat1,
cat2id.CategoryName as cat2,
cat3id.CategoryName as cat3,
cat4id.CategoryName as cat4,
cat5id.CategoryName as cat5,
cat6id.CategoryName as cat6,
cat7id.CategoryName as cat7,
cat8id.CategoryName as cat8,
cat9id.CategoryName as cat9,
cat10id.CategoryName as cat10
FROM users AS user
LEFT JOIN Category cat1id ON user.categoryid = cat1id.id
LEFT JOIN Category cat2id ON user.categoryid_2 = cat2id.id
LEFT JOIN Category cat3id ON user.categoryid_3 = cat3id.id
LEFT JOIN Category cat4id ON user.categoryid_4 = cat4id.id
LEFT JOIN Category cat5id ON user.categoryid_5 = cat5id.id
LEFT JOIN Category cat6id ON user.categoryid_6 = cat6id.id
LEFT JOIN Category cat7id ON user.categoryid_7 = cat7id.id
LEFT JOIN Category cat8id ON user.categoryid_8 = cat8id.id
LEFT JOIN Category cat9id ON user.categoryid_9 = cat9id.id
LEFT JOIN Category cat10id ON user.categoryid_10 = cat10id.id
WHERE user.id = 65447

谢谢!

Answer 1

如果您使用的是Mysql5,可以尝试编写视图.

所以

CREATE VIEW big_damn_query AS 
SELECT user.*,
cat1id.CategoryName as cat1,
cat2id.CategoryName as cat2,
cat3id.CategoryName as cat3,
cat4id.CategoryName as cat4,
cat5id.CategoryName as cat5,
cat6id.CategoryName as cat6,
cat7id.CategoryName as cat7,
cat8id.CategoryName as cat8,
cat9id.CategoryName as cat9,
cat10id.CategoryName as cat10
FROM users AS user
LEFT JOIN Category cat1id ON user.categoryid = cat1id.id
LEFT JOIN Category cat2id ON user.categoryid_2 = cat2id.id
LEFT JOIN Category cat3id ON user.categoryid_3 = cat3id.id
LEFT JOIN Category cat4id ON user.categoryid_4 = cat4id.id
LEFT JOIN Category cat5id ON user.categoryid_5 = cat5id.id
LEFT JOIN Category cat6id ON user.categoryid_6 = cat6id.id
LEFT JOIN Category cat7id ON user.categoryid_7 = cat7id.id
LEFT JOIN Category cat8id ON user.categoryid_8 = cat8id.id
LEFT JOIN Category cat9id ON user.categoryid_9 = cat9id.id
LEFT JOIN Category cat10id ON user.categoryid_10 = cat10id.id;

然后你的查询将是

SELECT * FROM big_damn_query bdq WHERE bdq.id = 65447