sql - SQL 记录和计数

Question

格式化 SQL Quert 以获取记录和计数时遇到问题。

SELECT
     eventStartDate
    ,eventTitle
    ,eventDesc
    ,eventTime
    ,count(eventID)
FROM GroupEvents 
WHERE eventStartDate = '10/14/2013'
GROUP BY eventStartDate

我想取回记录，这样我就可以像这样显示......（我可以格式化 - 只是向你展示我需要的东西）

There are 3 events for 10/14/2013   
    1. Dinner at Anthony's - 5:30pm
    2. Movie with New Members - 7:30pm
    3. Denny's - 11:00pm

谢谢你的帮助

Answer 1

在 SQL Server 中，您可以使用窗口函数解决此问题：

SELECT
     eventStartDate
    ,eventTitle
    ,eventDesc
    ,eventTime
    ,count(eventID)over(partition by eventStartDate) as eventCount
FROM GroupEvents 
WHERE eventStartDate = '10/14/2013'
GROUP BY eventStartDate

Answer 2

如果您使用的 RBDMS 不支持窗口函数，则需要分别确定每个事件日期的计数，然后加入此中间结果以获取计数和每个事件的详细信息：

SELECT
     ge.eventStartDate
    ,ge.eventTitle
    ,ge.eventDesc
    ,ge.eventTime
    ,q.eventCount
FROM GroupEvents ge
JOIN (
    SELECT
         eventStartDate
        ,count(eventID) AS eventCount
    FROM GroupEvents 
    GROUP BY eventStartDate
) q ON q.eventStartDate = ge.eventStartDate
WHERE ge.eventStartDate = '10/14/2013'