如何从n个表中只获取n条记录

Question

I have 3 tables with different content which all have datetime column.

I want to get last 10 records by datetime DESC from any of 3 tables.

Maybe 5 records from table 1, 3 records from table2, and 2 records from table3

How can I do that in mysql. Should I use Union ?

I tried both these queries:
Query1:

SELECT table1.*, table2.*, table3.* FROM table1, table2, table3 LIMIT 10

Query2:

( SELECT * FROM table 1 LIMIT 10 )
UNION
( SELECT * FROM table 2 LIMIT 10 )
UNION
( SELECT * FROM table 3 LIMIT 10 )

but these queries returns 30 records.

Answer 1

you have to write separately as you need separate limit

(IF having same columns)

SELECT * FROM table1 limit 5
UNION ALL
SELECT * FROM table2 limit 3
UNION ALL
SELECT * FROM table3 limit 2

UPDATE:

//if we need 10 rows in the result
SELECT * FROM table1,table2,table3 limit 10