SQL：具有不同条件的多个count语句

Question

Code:  Status  Cancel_Date
-----------------------------------
AAA    X       2012-02-01
AAA
BBB    X       2012-02-01
AAA    D       2012-01-01
AAA
BBB    
BBB    D       2012-02-01
BBB    X       2012-01-01

Code:  TotalNotXorD     TotalXorD
------------------------------------
AAA    2                1
BBB    1                2

select code, count(*) 
from table 
where status not in('X','D') 
group by code

select code, count(*) 
from table 
where status in('X','D') 
  and cancel_date >= '2012-02-01' 
group by code

有什么想法吗？

多谢了。

Answer 1

SELECT  a.code,
        COALESCE(b.totalNotXorD, 0 ) totalNotXorD,
        COALESCE(c.totalXorD, 0 ) totalXorD,
FROM    (SELECT DISTINCT Code FROM tableName) a
        LEFT JOIN
        (
            select code, count(*) totalNotXorD
            from table 
            where status not in('X','D') 
            group by code
        ) b ON a.code = b.code
        LEFT JOIN
        (
            select code, count(*) totalXorD
            from table 
            where status in('X','D') 
              and cancel_date >= '2012-02-01' 
            group by code
        ) c ON a.code = c.code

或者简单地执行case

SELECT  Code,
        SUM(CASE WHEN status NOT IN ('X','D') OR status IS NULL THEN 1 ELSE 0 END) TotalNotXorD,
        SUM(CASE WHEN status IN ('X','D') AND cancel_date >= '2012-02-01' THEN 1 ELSE 0 END) TotalXorD  
FROM    tableName
GROUP   BY Code