In this article, I will cover a bit about the LIKE operator, including how it works, and a bit of history about why it is like it is. After establishing this, I will discuss a bit about how you can (and should) use the LIKE operator in your CHECK constraints to strengthen your data integrity.
The LIKE Operator
The LIKE operator has been in SQL since the very beginning. It’s a very weak form of pattern matching, that has only two simple wildcards. The wildcards are ‘_‘ (underscore) and ‘%‘ (percent). They respectively stand for any single character and for