This function is similar to the ISNUMERIC native function, but tests for a valid integer. ISNUMERIC can return false positive results when testing for a valid integer. For example this select returns a value of 1 (true):
For 6.x and 7.0, you can easily convert it to a procedure.
A Normalization Primer
For most DBAs, normalization is an understood concept, a bread and butter bit of knowledge. However, it is not at all unusual to review a database design by a development group for an OLTP (OnLine Transaction Processing) environment and find that the schema chosen is anything but properly normalized. This article by Brian Kelley will give you the core knowledge to data model.