要统计多张表的总数要怎么做
比方说有12张表 tab_1(1月份),tab_2(2月份).........tab_12(12月份).
select count(*) from tab_1 那怎么把12张表的总数都统计出来,写一条语句!!
[解决办法]
select sum(num) from
(select count(*) as num from tab_1
union all
select count(*) as num from tab_2
..
..
select count(*) as num from tab_12
)
