两个表都有一个字段class,想统计两个表里以class分类的总共有多少个
select class,count( *) as total from table1 group by class如果我两个表分别为table1,table2,我想分别统计出来,如何做呢
select class,count( *) as total from table1 group by class如果我两个表分别为table1,table2,我想分别统计出来,如何做呢
UNION ALL
select class,count( *) as total,2 from table2 group by classselect class,count( *) as total from (SELECT * FROM table1
UNION ALL
SELECT * FROM table2
) group by class
UNION ALL
SELECT * FROM table2
) T group by class
select class,count(*) as total from table1 group by class
union all
select class,count(*) as total from table2 group by class
)
group by class
select class,sum(total) from (
select class,count(*) as total from table1 group by class
union all
select class,count(*) as total from table2 group by class
) t
group by class