比如有这样多个表tb1,tb2,tb3,.....,tb20,
我希望查询每个表中的nYear,nMonth,salary
也就是希望以下结果一次查询:
select nYear,nMonth,salary from tb1 where nMonth=12;
select nYear,nMonth,salary from tb2 where nMonth=12;
select nYear,nMonth,salary from tb3 where nMonth=12;
...
select nYear,nMonth,salary from tb20 where nMonth=12;
怎么弄呢?
我希望查询每个表中的nYear,nMonth,salary
也就是希望以下结果一次查询:
select nYear,nMonth,salary from tb1 where nMonth=12;
select nYear,nMonth,salary from tb2 where nMonth=12;
select nYear,nMonth,salary from tb3 where nMonth=12;
...
select nYear,nMonth,salary from tb20 where nMonth=12;
怎么弄呢?
select *,'b1' as bm from tb1
union all
select *,'b2' as bm from tb2
union all
...
select *,'bn' as bm from tbn) a
where nMonth=12;
select *,'b1' as bm from tb1
union all
select *,'b2' as bm from tb'
at line 1
是错误提示
SELECT *,'b1' AS bm FROM tb1
UNION ALL
SELECT *,'b2' AS bm FROM tb2
) a
WHERE nMonth=12;你的代码是什么、