mysql - 在一个语句中计算多个

Question

我有一个表格，其中包含数据标题和插入数据的日期。现在我想做一些统计来统计它。

我可以在一个sql语句中进行多次计数吗？就像从日期列一样，我想计算这个月有多少，今年有多少，直到选择月份。是否可以？如果是，怎么办？

这就是我现在想到的。

SELECT a.trigger_type_code
     , c.trigger_name
     , COUNT(*) AS number
FROM issue_trigger a 
  INNER JOIN cs_issue b
    ON b.issue_id = a.issue_id
  INNER JOIN ref_trigger_type c
    ON c.trigger_type_code = a.trigger_type_code
WHERE MONTH(b.created_date) = '05'
  AND YEAR(b.created_date) = '2011' 
GROUP BY trigger_type_code,trigger_name

这只是一个计数。帮助。:(

Answer 1

你可以使用case:

select  sum(case when MONTH(b.created_date) = '05' 
            AND YEAR(b.created_date) = '2011' then 1 end) as Count_2011_05
,       sum(case when YEAR(b.created_date) = '2011'
            then 1 end) as Count_2011
from    ... etc ...