Apply mysql query to each table in a database

Question

is there a way to apply a query to each table in a mysql database?

Something like

SELECT count(*) FROM {ALL TABLES}
-- gives the number of count(*) i         


        

Answer 1

if tables are related by any field you can use alias of tables like

select count(*) from table1 tb1, table2 tb2, table3 tb3 where
tb1.field1 = tb2.field2 and tb2.field2 = tb3.field3

similary,

delete from table1 tb1, table2 tb2, table3 tb3 where
tb1.field1 = tb2.field2 and tb2.field2 = tb3.field3

you can include conditions as per you requirements.

If tables have no relation then use below

SELECT
  (SELECT COUNT(*) FROM table1 WHERE someCondition) as count1, 
  (SELECT COUNT(*) FROM table2 WHERE someCondition) as count2,
  (SELECT COUNT(*) FROM table3 WHERE someCondition) as count3

you can remove where clause if there is no conditions.

OUTPUT:

|count1 | count2 | count3|

|50 |36 |21 |