Question

请帮助我进行此查询，我有此数据

customeid | param
1001      |  A
1001      |  B
1001      |  C
1002      |  B
1002      |  A
1003      |  A
1003      |  B
1004      |  A

我需要区分自定义，我使用此查询，但结果不正确

SELECT
  COUNT(DISTINCT IF(param not in ('A'),1,0))
FROM
  table

输出结果

count   
  3 (from customeid 1001,1002,1003)

如果参数不在A中并且无法在何处添加查询，如何区分customeid

Answer 1

您将count与if一起使用distinct来判断没有问题，但是有问题，如果满足条件，则需要返回customeid，否则您需要返回null

您可以遵循此查询。

SELECT
  COUNT(DISTINCT IF(param not in ('A'),customeid,NULL))
FROM
  table

sqlfiddle

注意

COUNT在该值为null时不会累积

Answer 2

使用case when和聚合函数group by

 select customeid,count(*) as Count
 from (    
    select (case when param!='A' then customeid else end) as customeid    from your_table
) T group by customeid

Answer 3

select customeid,count(customeid)
from table
where param <>'A'
group by customeid

Answer 4

SELECT DISTINCT COSTUMEID, COUNT(DISTINCT (PARAM))
FROM TABLE 
WHERE PARAM NOT IN (('A'),1,0) 
GROUP BY COSTUMEID

计数如果MySql与众不同

4 个答案: