复杂的SQL查询

Question

有一个客户表。我想在一个查询中列出活动和非活动状态。我怎么能这样做？

SELECT count(*) as ACTIVE, 
count(*) as INACTIVE 
FROM V_CUSTOMER 
WHERE STATUS='a' AND STATUS='i'

Answer 1

我们可以使用CASE语句翻译STATUS的两个值：

SELECT 
    sum(case when STATUS = 'a' then 1 else 0 end) as ACTIVE 
    , sum(case when STATUS = 'd' then 1 else 0 end) as DEACTIVE 
FROM V_CUSTOMER 

除非有大量具有STATUS其他值的记录，否则不需要WHERE子句，在这种情况下使用OR而不是AND：

WHERE STATUS='a' OR STATUS='d'         

Answer 2

尝试使用group by：

SELECT count(*), STATUS FROM V_CUSTOMER
Where STATUS='a' OR STATUS='d'
GROUP BY STATUS

Answer 3

SELECT count(decode(status,'a',1)) as ACTIVE, 
count(decode(status,'d',1)) as DEACTIVE 
FROM V_CUSTOMER 
WHERE STATUS='a' or STATUS='d' 

Answer 4

我认为你需要这样的东西：

select Status, count(*) from V_Customer
where STATUS='a' or STATUS='d'
group by STATUS

这将为您提供每个状态的记录数。