Count Year,Month,Day

• Deny Christian

  SSCrazy

  Points: 2297

  More actions

  January 19, 2017 at 12:28 pm

  #334123

  Comments posted to this topic are about the item Count Year,Month,Day

• John R. Hanson

  SSC-Addicted

  Points: 442

  More actions

  January 25, 2017 at 11:47 am

  #1924932

  Deny Christian - Thursday, January 19, 2017 12:28 PM

  Comments posted to this topic are about the item Count Year,Month,Day

  There are many ways this article could be improved.
  1. Provide a script with data for the example.
  2. Explain why you believe you need global variables.
  3. Explain why you believe you need a cursor.
  4. Explain how this works in all use cases. (e.g. Leap years, months with different numbers of days)
  5. Provide some analysis of how many reads and writes this query performs during execution. (for bonus points, try 10 items in inventory versus 10,000.
  6. Explain to new coders that you are using the modulus operator.
  7. The singular of Year, Month, and Day versus the plural Years, Months, and Days should be handled.

  Look forward to seeing a redo of this article.

• paulo.margarido

  Ten Centuries

  Points: 1245

  More actions

  January 26, 2017 at 4:38 am

  #1925021

  i think this can be related to this post:

  
  COUNTING-TIME-DIFFERENCE-IN-YEAR-MONTH-DAYS

• JohnCurrie

  SSC Veteran

  Points: 269

  More actions

  January 26, 2017 at 7:28 am

  #1925055

  You could try the following, substituting in relevant dates in @d1 and @d2:
  declare @d1 datetime = '3-jan-2000'
    ,    @d2 datetime = '2-may-2000'

  select isnull(cast(nullif(case    when datepart(month, @d1) > datepart(month, @d2)
                                then datediff(year, @d1, @d2) - 1
                                else datediff(year, @d1, @d2)
                         end, 0) as varchar)
             + case    when (select case when datepart(month, @d1) > datepart(month, @d2)
                                then datediff(year, @d1, @d2) - 1
                                else datediff(year, @d1, @d2)
                         end) > 1 then ' Years, ' else ' Year, ' end, '') +
     isnull(cast(nullif(case when datediff(day, dateadd(month, datediff(month, @d1, @d2), @d1), @d2) < 0
                                then (datediff(month, @d1, @d2) - 1) % 12
                                else datediff(month, @d1, @d2) % 12
                         end, 0) as varchar)
            + case when (select case when datediff(day, dateadd(month, datediff(month, @d1, @d2), @d1), @d2) < 0
                                then (datediff(month, @d1, @d2) - 1) % 12
                                else datediff(month, @d1, @d2) % 12
                         end) > 1 then ' Months, ' else ' Month, ' end, '') +
     isnull(cast(nullif(case when datediff(day, dateadd(month, datediff(month, @d1, @d2), @d1), @d2) < 0
                                then datediff(day, dateadd(month, datediff(month, @d1, @d2) -1, @d1), @d2)
                                else datediff(day, dateadd(month, datediff(month, @d1, @d2), @d1), @d2)
                         end, 0) as varchar)
            + case when (select case when datediff(day, dateadd(month, datediff(month, @d1, @d2), @d1), @d2) < 0
                                then datediff(day, dateadd(month, datediff(month, @d1, @d2) -1, @d1), @d2)
                                else datediff(day, dateadd(month, datediff(month, @d1, @d2), @d1), @d2)
                         end) > 1 then ' Days' else ' Day' end, '')


• ChrisM@Work

  SSC Guru

  Points: 186127

  More actions

  January 26, 2017 at 7:36 am

  #1925057

  Deny Christian - Thursday, January 19, 2017 12:28 PM

  Comments posted to this topic are about the item Count Year,Month,Day

  Did you try this yet? It's on your original thread.

  ^{“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw}

  For fast, accurate and documented assistance in answering your questions, please read this article.
  Understanding and using APPLY, (I) and (II) Paul White
  Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden

• ChrisM@Work

  SSC Guru

  Points: 186127

  More actions

  January 26, 2017 at 7:45 am

  #1925061

  Msg 241, Level 16, State 1, Line 44

  Conversion failed when converting date and/or time from character string.

  ^{“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw}

  For fast, accurate and documented assistance in answering your questions, please read this article.
  Understanding and using APPLY, (I) and (II) Paul White
  Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden