MySql 查询 : include days that have COUNT(id) == 0 but only in the last 30 days

Question

我正在执行一个查询，以从我们的数据库中获取过去 30 天每天的构建次数。但也需要它来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，我如何修改它以包括具有 COUNT(id) == 0 但仅在过去 30 天内的天数。

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，然后左连接到构建表。

像这样:

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);