从哪个表中检索数据

本文介绍了从哪个表中检索数据的处理方法，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小编来一起学习吧！

问题描述

SELECT username,
       password,
FROM table1
WHERE username = :username
UNION ALL
SELECT username,
       password,
FROM table2
WHERE username = :username

我想从哪个表中查找数据是从 table1 还是 table2 中检索到的而且这些表中插入的数据是唯一的

I want to find from which table the data as been retrieved whether from table1 or table2And ya the inserted data in these tables are unique

提前致谢

推荐答案

添加包含此信息的列:

SELECT 'table1' as which, username, password
FROM table1
WHERE username = :username
UNION ALL
SELECT 'table2' as which, username, password
FROM table2
WHERE username = :username;

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