如题。比如想查找满足条件的行数。满足1条件:SELECT COUNT(*) AS Expr1 FROM table WHERE (Value = 1)满足2条件:SELECT COUNT(*) AS Expr1 FROM table WHERE (Value = 2)满足3条件:SELECT COUNT(*) AS Expr1 FROM table WHERE (Value = 3)......有没有办法可以实现把这三条查询语句放到一起执行起来。达到比如这样的效果SELECT COUNT(*) AS Expr1,COUNT(*) AS Expr2,COUNT(*) AS Expr3 from table .........................
sum(case when Value = 2 then 1 else 0 end)AS Expr2,
sum(case when Value = 3 then 1 else 0 end)AS Expr3
from [table]
(SELECT COUNT(*) FROM table WHERE (Value = 1)) AS Expr1,
(SELECT COUNT(*) FROM table WHERE (Value = 2)) AS Expr2,
(SELECT COUNT(*) FROM table WHERE (Value = 3)) AS Expr3
from table
SELECT sum(case when Value = 1 then 1 else 0 end) AS Expr1,
sum(case when Value = 2 then 1 else 0 end) AS Expr2,
sum(case when Value = 3 then 1 else 0 end) AS Expr3
FROM table
group by ..
--2
SELECT COUNT(*) AS Expr1 FROM table WHERE (Value = 1) union all
SELECT COUNT(*) AS Expr1 FROM table WHERE (Value = 2) union all
SELECT COUNT(*) AS Expr1 FROM table WHERE (Value = 3)
sum(case when Value = 1 then 1 else 0 end) AS Expr1
sum(case when Value = 2 then 1 else 0 end) AS Expr2
sum(case when Value = 3 then 1 else 0 end) AS Expr3
from tb
(SELECT COUNT(*) AS Expr1 FROM table WHERE (Value = 1)) AS Expr1, (SELECT COUNT(*) AS Expr1 FROM table WHERE (Value = 2)) AS Expr2, (SELECT COUNT(*) AS Expr1 FROM table WHERE (Value = 3)) AS Expr3
特别感谢sql_sf。结贴。