MySql查询：包括具有COUNT（id）== 0但仅在最近30天内的天

Question

我正在查询以获取最近30天每天从数据库中获取的构建数量。但是现在已经需要标记没有构建的日子。

在我的WHERE子句中，我使用Submittime来确定是否有构建，如何修改它以包括COUNT（id）== 0但仅在最近30天内的天。

原始查询：

   SELECT COUNT(id) AS 'Past-Month-Builds', 
          CONCAT(MONTH(submittime), '-', DAY(submittime)) as 'Month-Day' 
     FROM builds 
    WHERE DATE(submittime) >= DATE_SUB(CURDATE(), INTERVAL 30 day) 
 GROUP BY MONTH(submittime), DAY(submittime);

我尝试过的

   SELECT COUNT(id) AS 'Past-Month-Builds', 
          CONCAT(MONTH(submittime), '-', DAY(submittime)) as 'Month-Day' 
     FROM builds 
    WHERE DATE(submittime) >= DATE_SUB(CURDATE(), INTERVAL 30 day) 
       OR COUNT(id) = 0
 GROUP BY MONTH(submittime), DAY(submittime);

Answer 1

您需要一个日期表，然后左联接到builds表。

像这样的东西：

SELECT 
    COUNT(id) AS 'Past-Month-Builds', 
    CONCAT(MONTH(DateTable.Date), '-', DAY(DateTable.Date)) as 'Month-Day' 
FROM DateTable
    LEFT JOIN builds ON DATE(builds.submittime) = DateTable.Date
WHERE DateTable.Date >= DATE_SUB(CURDATE(), INTERVAL 30 day) 
GROUP BY MONTH(submittime), DAY(submittime);