Trouver la valeur de colonne minimale et maximale d'une colonne commune dans toutes les tables d'une base de données SQL Server 2008

Quelque chose comme ce qui suit devrait fonctionner

DECLARE @C1           AS CURSOR,
        @TABLE_SCHEMA SYSNAME,
        @TABLE_NAME   SYSNAME,
        @HasCreated   BIT,
        @HasUpdated   BIT,
        @MaxDate      DATETIME,
        @MinDate      DATETIME,
        @SQL          NVARCHAR(MAX) 

SET @C1 = CURSOR FAST_FORWARD FOR 
SELECT TABLE_SCHEMA,
       TABLE_NAME,
       COUNT(CASE
               WHEN COLUMN_NAME = 'CREATED_DATETIME' THEN 1
             END) AS HasCreated,
       COUNT(CASE
               WHEN COLUMN_NAME = 'UPDATED_DATETIME' THEN 1
             END) AS HasUpdated
FROM   INFORMATION_SCHEMA.COLUMNS
WHERE  COLUMN_NAME IN ( 'CREATED_DATETIME', 'UPDATED_DATETIME' )
GROUP  BY TABLE_SCHEMA,
          TABLE_NAME 


OPEN @C1;

FETCH NEXT FROM @C1 INTO @TABLE_SCHEMA , @TABLE_NAME , @HasCreated , @HasUpdated ;
WHILE @@FETCH_STATUS = 0
BEGIN

SET @SQL = N'
SELECT @MaxDate = MAX(D),
       @MinDate = MIN(D)
FROM   ' + QUOTENAME(@TABLE_SCHEMA) + '.' + QUOTENAME(@TABLE_NAME) + N' 
       CROSS APPLY (VALUES ' + 
                  CASE WHEN @HasCreated = 1 THEN N'(CREATED_DATETIME),' ELSE '' END + 
                  CASE WHEN @HasUpdated = 1 THEN N'(UPDATED_DATETIME),' ELSE '' END + N'
                           (@MaxDate),
                           (@MinDate)) V(D) 

'

EXEC sp_executesql 
    @SQL,
    N'@MaxDate datetime OUTPUT, @MinDate datetime OUTPUT', 
    @MaxDate = @MaxDate OUTPUT, 
    @MinDate = @MinDate OUTPUT

  FETCH NEXT FROM @C1 INTO @TABLE_SCHEMA , @TABLE_NAME , @HasCreated , @HasUpdated ;
END

SELECT @MaxDate AS [@MaxDate], @MinDate AS [@MinDate]