sql 中，如何获取两个日期之前月数、周数、天数

1、获取两个日期之间的月数、周数、天数语法

   --1、获取两个日期之间的月数、周数、天数

    --1.1)声明参数

    declare @startDate varchar(20)

    declare @endDate varchar(20)

    --1.2）获取两个日期直接的月数

    select DATEDIFF(MM,@startDate,@endDate)

     --1.3）获取两个日期直接的月数

    select DATEDIFF(WW,@startDate,@endDate)

     --1.4）获取两个日期直接的月数

    select DATEDIFF(DD,@startDate,@endDate)

2、测试用例

    --2、测试用例

    --2.1）获取指定日期和当前日期直接的月数

    select DATEDIFF(MM,'2017-08-12 11:12:23',GETDATE()) as 月数

    --2.2）获取指定日期和当前日期直接的周数

    select DATEDIFF(WW,'2017-08-12 11:12:23',GETDATE()) as 周数

    --2.3）获取指定日期和当前日期直接的月数

    select DATEDIFF(DD,'2017-08-12 11:12:23',GETDATE()) as 天数

3、测试结果

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