Every programmer should embrace and use regular expressions (INCLUDING Database programmers).
There are many places where regular expressions can be used to reduce a 20 line piece of code into a
1 liner. Why write 20 lines of code when you can write 1.
Regular expressions are a domain language just like SQL. Just like SQL they are embedded in many places. You have them in your program editor.
You see it in sed, grep, perl, PHP, Python, VB.NET, C#,
you can use them in SQL statements, domain definitions and check constraints. You can mix
regular expressions with SQL. When you mix the two domain languages, you can do enchanting things with a flip of a wrist that
would amaze your less informed friends. Embrace the power of domain languages and mix it up. PostgreSQL
makes that much easier than any other DBMS we can think of.
For more details on using regular expressions in PostgreSQL, check out the manual pages Pattern Matching in PostgreSQL
The problem with regular expressions is that they are slightly different depending on what language environment you are
running them in. Different enough to be frustrating. We'll just focus on their use in PostgreSQL, though these lessons
are applicable to other environments.