SQL Server和日期+ 1个结果 [英] SQL Server and date + 1 result

问题描述

对于SQL Server。说，如果我有一个带有[myDate]列的表，该表的类型为datetime，那么在以下情况下向其添加1意味着什么？

In case of the SQL Server. Say, if I have a table with [myDate] column that is of the type datetime, what would adding 1 to it mean in the following context?

SELECT * 
  FROM [myTable] 
 WHERE [myDate] + 1 > @someDate

推荐答案

添加一天（恰好是24小时）

It adds one day (exactly 24 hours)

但是，您的查询通过这种方式更加正确。如果该列中有一个，则该列上的函数或处理通常会使索引使用无效

However, your query is more correct this way. The function or processing on the column usually invalidates index usage if there is one of that column

WHERE [myDate] > @someDate - 1

OR

WHERE [myDate] > DATEADD(day, -1, @someDate)

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