SQL Server : How to test if a string has only digit characters

Question

I am working in SQL Server 2008. I am trying to test whether a string (varchar) has only digit characters (0-9). I know that the IS_NUMERIC function can give spurious results.

Answer 1

DECLARE @x int=1
declare @exit bit=1
WHILE @x<=len('123c') AND @exit=1
BEGIN
IF ascii(SUBSTRING('123c',@x,1)) BETWEEN 48 AND 57
BEGIN
set @x=@x+1
END
ELSE
BEGIN
SET @exit=0
PRINT 'string is not all numeric  -:('
END
END