I can't figure out how to select just the values in a field that are alpha. For example, instead of hard coding something like:
where Sales_Code in ('RT'N, 'EXC', 'DMG')
I need to make this "dynamic" to always include all Sales_Codes that would be alpha characters only and omit the codes that are numeric. There won't be any alpha-numeric codes, like XY1 or 2DE.