mysql - 在 MYSQL 中加入 5 数据库

Question

我有 5 个数据库，假设他们的名字是A B C D E

所有数据库具有相同的表/结构/字段

我想使用表从 5 个数据库中获取结果SMSOutgoing，该字段是uid

它看起来像这样：

SELECT * OR JOIN 5 database A B C D E F
FROM `table` SMSOutgoing
WHERE uid = 1

不是所有的数据库都有uid=1，需要显示哪个数据库有结果

我运行 SMS Gateway，每个电话/1 个号码使用 1 个数据库，这就是为什么有这么多不同的数据库。

我花了几个小时来解决它，但总是出错，我认为我遵循了错误的指南（在 1 个数据库中加入多个表）

我迷路了，请帮忙，谢谢

Answer 1

听起来您想在 SMSOutgoing 表中列出包含 uid = 1 的数据库。如果是这样，您应该可以使用UNION：

SELECT DISTINCT 'DatabaseA' WhichDb
FROM DatabaseA.SMSOutgoing 
WHERE uid = 1
UNION
SELECT DISTINCT 'DatabaseB' WhichDb
FROM DatabaseB.SMSOutgoing 
WHERE uid = 1
UNION
...
UNION
SELECT DISTINCT 'DatabaseF' WhichDb
FROM DatabaseF.SMSOutgoing 
WHERE uid = 1

I used DISTINCT in case you could have multiple uid in the same table -- that may be unnecessary.

EDIT: From your comments, it sounds like you just want the results:

SELECT *
FROM DatabaseA.SMSOutgoing 
WHERE uid = 1
UNION
SELECT *
FROM DatabaseB.SMSOutgoing 
WHERE uid = 1
UNION
...
UNION
SELECT *
FROM DatabaseF.SMSOutgoing 
WHERE uid = 1

You may need to use UNION ALL if you might have duplicates...