Question

SQL Server Express 2014 ---您好，我对SQL和进行查询非常陌生。基本上，我希望提取在同一天开始和结束的事件。

*正在询问的问题：“在“参与度”表中，显示同一天内开始和停止的所有参与度。” 24小时之间发生的事件。

我似乎无法编写正确的语法。到目前为止我的进度...

SELECT EngagementNumber,StartDate, StartTime, Stoptime, 
FROM Engagements
WHERE CAST(Stoptime-Starttime AS INTERGER)=1

Answer 1

发布SQL查询问题时，始终最好提供数据样本和一些有关字段的表信息。

我在下面包括的是一些基于原始查询的查询，这些查询都旨在以略有不同的方式显示该数据集。

在旁注。我不确定为什么您的where子句中有Stoptime-Starttime并保留了它。但是我确实讨厌在where子句中有聚合。这是个人选择，但可能要牢记，我通常使用其他子句，例如“ HAVING”。

下面是查询集，请告诉我其中的一个是否适合您的目的，如果需要，我可以进行扩展。

---- Your original query (You had and extra , in there)
SELECT 
    EngagementNumber,
    StartDate, 
    StartTime, 
    Stoptime
FROM Engagements
WHERE 
    CAST(Stoptime-Starttime AS INTERGER)=1

---- This will Get all events on the day, take their stop and start then sum all of it together
---- This might not be what you want, its handy for counting how many events are on a day or
---- the total effect of a day, with a group by you must be working with aggregates
SELECT 
    StartDate, 
    COUNT(EngagementNumber) AS NumberofEvents,
    SUM(Stoptime-Starttime) AS TotalTimeTaken
FROM Engagements
WHERE 
    CAST(Stoptime-Starttime AS INTERGER)=1
GROUP BY
    StartDate

---- This will pull all the values and sort them by date
---- It will give you a line for every Engagement but list all the 01/01 and then 02/01
SELECT 
    EngagementNumber,
    StartDate, 
    StartTime, 
    Stoptime
FROM Engagements
WHERE 
    CAST(Stoptime-Starttime AS INTERGER)=1
ORDER BY 
    StartDate

---- This includes a Date parameter in the where clause to allow you to bring
---- back a single day of engagements.
SELECT 
    EngagementNumber,
    StartDate, 
    StartTime, 
    Stoptime
FROM Engagements
WHERE 
    CAST(Stoptime-Starttime AS INTERGER)=1
    AND StartDate = ?

SQL 2014如何从一天发生的事件中提取数据？

1 个答案: