You should try printing your commands when they yield errors. If you issued this instead of executing it:
PRINT @cmd;
You would see that this:
WHERE ValueDate BETWEEN ' + CONVERT(VARCHAR,@b,121) + ' AND ' + CONVERT(VARCHAR,@E,121)
Yields this:
WHERE ValueDate BETWEEN 2012-07-01 AND 2014-01-25
Which, since those look to SQL Server like three integers with a couple of subtraction operators, becomes:
WHERE ValueDate BETWEEN 2004 AND 1988
Which isn't even a valid BETWEEN operation, even if it could translate those to dates.
What you should be doing is passing these as proper parameters, e.g.
SET @cmd = 'DELETE FROM dbo.DateTable -- always use SCHEMA prefix
WHERE ValueDate BETWEEN @b AND @e;';
EXEC sp_executesql @cmd, N'@b DATE, @e DATE', @b, @e;
If any of these columns are DATETIME, not DATE, you really should not be using BETWEEN at all. Instead:
WHERE ValueDate >= @b AND ValueDate < DATEADD(DAY, 1, @e);
Please read:
- http://sqlblog.com/blogs/aaron_bertrand/archive/2009/10/09/bad-habits-to-kick-declaring-varchar-without-length.aspx
- http://sqlblog.com/blogs/aaron_bertrand/archive/2009/10/11/bad-habits-to-kick-avoiding-the-schema-prefix.aspx
- http://sqlblog.com/blogs/aaron_bertrand/archive/2011/10/19/what-do-between-and-the-devil-have-in-common.aspx
- http://sqlblog.com/blogs/aaron_bertrand/archive/2009/09/03/ladies-and-gentlemen-start-your-semi-colons.aspx
As for the overall requirement of repeating this query against all date columns in the database, here is how I would do it (I've looked at the SO question you reference, and it just shows how to do this for one table):
DECLARE @b DATE = '2012-07-01', @e DATE = '2014-01-25',
@sql NVARCHAR(MAX) = N'';
SELECT @sql += N'
DELETE ' + QUOTENAME(s.name)
+ '.' + QUOTENAME(t.name) + '
WHERE ' + QUOTENAME(c.name) + ' >= @b
AND ' + QUOTENAME(c.name) + ' < DATEADD(DAY, 1, @e);'
FROM sys.tables AS t
INNER JOIN sys.schemas AS s
ON t.[schema_id] = s.[schema_id]
INNER JOIN sys.columns AS c
ON t.[object_id] = c.[object_id]
WHERE c.system_type_id IN (40,42,43,58,61);
-- or just = 40 if you're only interested in DATE columns
PRINT @sql;
-- EXEC sp_executesql @sql, N'@b DATE, @e DATE', @b, @e;