选择多个表的查询

Question

I have tables A01, B01, C01 and so on... all with identical structure.

+----+-----+
| ID | val |
+----+-----+
|  1 | a   |
|  2 | b   |
+----+-----+

+----+-----+
| id | val |
+----+-----+
|  1 | c   |
|  2 | d   |
+----+-----+

+----+-----+
| id | val |
+----+-----+
|  1 | e   |
|  2 | f   |
+----+-----+

Is it possible to have a query that displays the "val" column from all tables ?

Also so that if a new tables is created the query should not be changed.

I am going to run this on a PHP webpage.

Answer 1

Create a view with union or union all clause with all your required tables. If you create a table in future , just alter the view to include that table as well.

CREATE VIEW AS MYVIEW
SELECT VAL FROM A01 UNION ALL
SELECT VAL FROM B01...

Always use same query to get data:

SELECT VAL FROM MYVIEW