SQL, how to get the number of months, weeks, and days before two dates

1. Get the number of months, weeks, and days between two dates syntax

   --1. Get the number of months, weeks, and days between two dates    --1.1) Declaring parameters    Declare @startDate varchar( -)    Declare @endDate varchar( -)    --1.2) Get the number of months directly on the two date    Select DATEDIFF(MM,@startDate,@endDate)     --1.3) Get the number of months directly on the two date    Select DATEDIFF(WW,@startDate,@endDate)     --1.4) Get the number of months directly on the two date    Select DATEDIFF(DD,@startDate,@endDate)

2. Test Cases

    --2. Test Cases    --2.1) Gets the number of months directly from the specified date and the current date    Select DATEDIFF(MM,'2017-08-12 11:12:23',GETDATE()) asnumber of months--2.2) Gets the number of weeks directly from the specified date and the current date    Select DATEDIFF(WW,'2017-08-12 11:12:23',GETDATE()) asWeek number--2.3) Gets the number of months directly from the specified date and the current date    Select DATEDIFF(DD,'2017-08-12 11:12:23',GETDATE()) asDays

3. Test results

SQL, how to get the number of months, weeks, and days before two dates