SQL查询查找，天气输入的记录是否是当天的第一条记录 [英] Sql Query to find, weather the record entered is the first record or not on that day

问题描述

假设我们有一个表，其中包含UserID，日历日期和taskName作为列.请让我知道，从sql查询天气中，我们可以发现，对于用户ID，它是否是当天在表中输入的第一条记录.

Suppose we have a table with UserID ,Calendar date and taskName as columns. Please let me know that from sql Query weather we can find that for a user id is it the first record entered in the table on that day or not.

推荐答案

尝试这个:

Try this:

DECLARE @TODAY DATE
SET @TODAY = CONVERT(VARCHAR(10), GETDATE(), 111)
SELECT COUNT(*) FROM myTable WHERE Calendar >= @TODAY

如果为零，则从午夜开始没有任何条目.

[edit]更改了表名和列名-OriginalGriff [/edit]

If it is zero, then there are no entries since midnight.

[edit]Changed table and column names - OriginalGriff[/edit]

不确定该问题，但是如果您想为单个日期的用户查找第一条记录，那么也许类似于以下内容.它应该为今天的给定用户获取第一条记录

Not sure about the question, but if you want to find the first record for a user fo a single date, then perhaps something like the following. It should fetch the first record for given user for today

SELECT *
FROM TableName t1
WHERE UserId = <userid_goes_here>
AND   CalendarDate >= CAST( GETDATE() AS DATE)
AND   NOT EXISTS (SELECT 1
                  FROM TableName t2
                  WHERE t2.UserId = t1.UserId
                  AND   t2.CalendarDate < t1.CalendarDate
                  AND   t2.CalendarDate >= CAST( GETDATE() AS DATE))</userid_goes_here>

您可以将GETDATE替换为正确的日期.

You can replace the GETDATE with a proper date.

这篇关于SQL查询查找，天气输入的记录是否是当天的第一条记录的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！