Removing non-numeric characters from a SQL Server field without UDFs or Regex

A great question came up in the SQL Community Slack today:

I saw this as a great modification on my earlier post, and wanted to show another way to implement the same solution.

Walking through the steps:

First, use sys.objects as our example “target” and assume the string has less than 2024 characters (spt..numbers isnt really reliable past that point.)

We substring out each character and compare it to the list of items we accept, and then collapse the list back in on itself.

At the end, I pull out sys.objects for comparison so you can see what sort or results you would get. Enjoy!