如何从结构相同但不相关的两个表中选择数据？ 的MySQL

Question

I'm new to MySQL and I'm working in a project where I have two tables (TABLE A and TABLE B), both tables have the same structure, same column names, etc but they are use for different tasks.

But in some part of code is required to show info about the two tables and I think that if they have the same structure and column names why not use the same query to display the info?

I read something about INNER JOIN and CROSS JOIN but not sure if they are only to related table by foreign keys

I would like to know too if is possible to have two queries like:

SELECT * FROM table_A..

SELECT * FROM table_B..

and then combine the results in the function like mysqli_fetch_assoc

Can you give me ideas how to achieve this or what to use? thanks.

Answer 1

查看MySQL UNION语法 ：

(SELECT * FROM table_A) UNION (SELECT * FROM table_B)