Denis Gobo shows that SQL Server check constraints support limited regular expression capabilities:
While SQL server does not support a full implementation of regular expression, you can do what the person asked for without a problem in T-SQL. Here is what the regular expression looks like
[DMOPT][0-9][0-9]
A constraint like that will allow allow the following alphabetic characters (D, M, O, P or T) followed by 2 numeric characters. Enough talking let’s look at some code, first create this table
Read on to see how this constraint works and for implementation code.