union all查詢統計總數量

select sum(a.b) as num from (

select count() as b from table_1 

union all 

select count() as b from table_2

) as a（注意這裡要取個别名）

 本文轉自 Lee_吉 51CTO部落格，原文連結:http://blog.51cto.com/12173069/2053757