Check only for numeric digits without using a loop

				
--**************************************
-- Name: Check only for numeric digits without using a loop
-- Description:The ISNUMERIC function in SQL60/65/70 checks for decimal & integer values. Hence characters like D, E are valid float representations & similarly ','. This is a simple logic that can check only for numeric digits without using a loop of any kind
-- By: Umachandar
--
--This code is copyrighted and has-- limited warranties.Please see http://www.Planet-Source-Code.com/vb/scripts/ShowCode.asp?txtCodeId=195&lngWId=5--for details.--**************************************

-- The numbers are hard-coded in the SELECT below but
-- use a NUMBERS table instead. This table can also be
-- used to solve several other problems quite easily.
declare @c varchar(10)
select @c = '12' + char(9)
if exists(select * from
		(select 1 as digit union all select 2 union all
			select 3 union all select 4 union all
			select 5 union all select 6 union all
			select 7 union all select 8 union all
			select 9 union all select 10) as n
		where ascii(substring(@c, digit, 1 )) not between 48 and 57 )
	print 'No'
else
	print 'Yes'
-- Or to check for unsigned integers alone
if patindex( '%[^0-9]%' , @c ) > 0
	print 'No'
else
	print 'Yes'