来自多个数据库表的MySQL联合 [英] Mysql union from multiple database tables

问题描述

我有一组数据库，这些数据库的表具有相同的模式.因此，我正在此表上执行UNION以显示所有数据库中的记录，效果很好.

I have a group of databases which have a table with same schema. So, i am doing a UNION on this table to show the records from all databases, which works nice.

但是，现在我必须检测哪一行属于哪个数据库/表，因为我需要修改该特定记录.我找到了此链接在获取UNION时遇到问题，但无法找到确定行<->表关系的逻辑.

But, now i have to detect which row belongs to which database/table, as i need to modify that particular record. I found this link on getting the UNION, but am unable to find the logic which determines row<->table relationship.

推荐答案

尝试一下:

(SELECT *, 'db1' as DB_NAME from db1..table1)
union
(SELECT *, 'db2' as DB_NAME from db2..table1)
union
(SELECT *, 'db3' as DB_NAME from db3..table1)
...

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