T-SQL and Case Statement

Question

I am having difficulty trying to find out why my t-sql string is coming up with an error message as you can see I have created this sql to pull information from other tables to create a capacity table, however something is not right and I cant figure out what it is. Can you help. Thanks in advance.

Error message:

Msg 206, Level 16, State 2, Line 32
Operand type clash: int is incompatible with date

SQL script:

DECLARE @PitchType_Skey INT
DECLARE @Site_Skey INT
DECLARE @Capacity INT
DECLARE @StartDate DATE
DECLARE @EndDate DATE

SET @PitchType_Skey = 1
SET @Site_Skey = 1
SET @Capacity = 0


WHILE (@Site_Skey < 127)

BEGIN
  IF @PitchType_Skey = 8

  BEGIN

    SET @PitchType_Skey = 1
    SET @Site_Skey = @Site_Skey + 1

  END

  IF (@Site_Skey < 127)

  BEGIN

    Set @Capacity = (SELECT SiteWeighting From Site Where Site_Skey = @Site_Skey)
    Set @Capacity = @Capacity * (SELECT PitchTypeWeighting From PitchType  Where PitchType_Skey = @PitchType_Skey)
    Set @Capacity = @Capacity * ((10*(100+((RAND()*40)-20)))*0.01)

    INSERT INTO Capacity2
    SELECT
      CASE
        WHEN YEAR(@StartDate) = 2010 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 1 THEN '01 May 2010'
        WHEN YEAR(@StartDate) = 2011 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 1 THEN '01 May 2011'
        WHEN YEAR(@StartDate) = 2012 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 1 THEN '01 May 2012'
        WHEN YEAR(@StartDate) = 2013 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 1 THEN '01 May 2013'
        WHEN YEAR(@StartDate) = 2014 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 1 THEN '01 May 2014'
        WHEN YEAR(@StartDate) = 2015 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 1 THEN '01 May 2015'

        WHEN YEAR(@StartDate) = 2010 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 2 THEN '1 Apr 2010'
        WHEN YEAR(@StartDate) = 2011 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 2 THEN '25 Mar 2011'
        WHEN YEAR(@StartDate) = 2012 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 2 THEN '10 Mar 2012'
        WHEN YEAR(@StartDate) = 2013 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 2 THEN '01 Apr 2013'
        WHEN YEAR(@StartDate) = 2014 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 2 THEN '01 Mar 2014'
        WHEN YEAR(@StartDate) = 2015 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 2 THEN '15 Mar 2015'

        WHEN YEAR(@StartDate) = 2010 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 3 THEN '1 Apr 2010'
        WHEN YEAR(@StartDate) = 2011 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 3 THEN '25 Mar 2011'
        WHEN YEAR(@StartDate) = 2012 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 3 THEN '10 Mar 2012'
        WHEN YEAR(@StartDate) = 2013 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 3 THEN '01 Apr 2013'
        WHEN YEAR(@StartDate) = 2014 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 3 THEN '01 Mar 2014'
        WHEN YEAR(@StartDate) = 2015 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 3 THEN '15 Mar 2015'

        WHEN YEAR(@StartDate) = 2010 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 4 THEN '01 Jan 2010'
        WHEN YEAR(@StartDate) = 2011 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 4 THEN '01 Jan 2011'
        WHEN YEAR(@StartDate) = 2012 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 4 THEN '01 Jan 2012'
        WHEN YEAR(@StartDate) = 2013 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 4 THEN '01 Jan 2013'
        WHEN YEAR(@StartDate) = 2014 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 4 THEN '01 Jan 2014'
        WHEN YEAR(@StartDate) = 2015 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 4 THEN '01 Jan 2015'

        ELSE NULL
      END as StartDate,

      CASE
        WHEN YEAR(@EndDate) = 2010 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 1 THEN '30 Sep 2010'
        WHEN YEAR(@EndDate) = 2011 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 1 THEN '30 Sep 2011'
        WHEN YEAR(@EndDate) = 2012 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 1 THEN '30 Sep 2012'
        WHEN YEAR(@EndDate) = 2013 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 1 THEN '30 Sep 2013'
        WHEN YEAR(@EndDate) = 2014 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 1 THEN '30 Sep 2014'
        WHEN YEAR(@EndDate) = 2015 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 1 THEN '30 Sep 2015'

        WHEN YEAR(@EndDate) = 2010 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 2 THEN '01 Nov 2010'
        WHEN YEAR(@EndDate) = 2011 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 2 THEN '05 Nov 2011'
        WHEN YEAR(@EndDate) = 2012 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 2 THEN '02 Nov 2012'
        WHEN YEAR(@EndDate) = 2013 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 2 THEN '08 Nov 2013'
        WHEN YEAR(@EndDate) = 2014 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 2 THEN '01 Nov 2014'
        WHEN YEAR(@EndDate) = 2015 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 2 THEN '03 Nov 2015'

        WHEN YEAR(@EndDate) = 2010 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 3 THEN '01 Nov 2010'
        WHEN YEAR(@EndDate) = 2011 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 3 THEN '05 Nov 2011'
        WHEN YEAR(@EndDate) = 2012 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 3 THEN '02 Nov 2012'
        WHEN YEAR(@EndDate) = 2013 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 3 THEN '08 Nov 2013'
        WHEN YEAR(@EndDate) = 2014 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 3 THEN '01 Nov 2014'
        WHEN YEAR(@EndDate) = 2015 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 3 THEN '03 Nov 2015'

        WHEN YEAR(@EndDate) = 2010 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 4 THEN '31 Dec 2010'
        WHEN YEAR(@EndDate) = 2011 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 4 THEN '31 Dec 2011'
        WHEN YEAR(@EndDate) = 2012 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 4 THEN '31 Dec 2012'
        WHEN YEAR(@EndDate) = 2013 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 4 THEN '31 Dec 2013'
        WHEN YEAR(@EndDate) = 2014 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 4 THEN '31 Dec 2014'
        WHEN YEAR(@EndDate) = 2015 AND (SELECT SiteWeighting FROM Site WHERE Site_Skey=@Site_Skey) = 4 THEN '31 Dec 2015'

        ELSE NULL
      END,

      ROUND(@Capacity,0) as Capacity,
      @PitchType_Skey, @Site_Skey

  END
  SET @PitchType_Skey = @PitchType_Skey + 1

END

Answer 1

You are inserting into the Capacity2 table without specifying which values go into which columns to put each value into. I'm guessing that this is the cause of the problem, and it's trying to put your one of your other integer values into your start date column.

You haven't posted your schema so I can only guess your column names, but I suggest you change the insert part of your script to be like:

INSERT INTO Capacity2 (StartDate, EndDate, Capacity, PitchTypeKey, Site_SKey)
SELECT 
   CASE 
     WHEN ...

That way there is no ambiguity as to which value you want inserted into which column.