如何从SQL Server中的两个不同表中选择相同数量的记录

Question

How can I select the same number of records from two different tables in SQL Server?

For example, I have a table A with 10 records and table B with 15 records; how can I select 10 records from A and 10 records from B ?

Answer 1

If both the tables have same number and type of columns. Then use union or union all

Select col1,col2,col3 from table1
union
Select col1,col2,col3 from table2

Answer 2

Something like that?

    SELECT col1,col2,col3
    FROM TABLE_A

    UNION 

    SELECT TOP (SELECT COUNT(*) FROM TABLE_A) col1,col2,col3
    FROM TABLE_B