In every programming language, in every program, and in every module, error handling is an important thing. Everything is expected to go wrong once in a while, and therefore it is vital and of key importance to handle errors properly and professionally. In PL/pgSQL, you can use EXCEPTION blocks to handle errors. The idea is that if the BEGIN block does something wrong, the EXCEPTION block will take care of it and handle the problem correctly. Just like many other languages, such as Java, you can react on different types of errors and catch them separately.
In the following example, the code might run into a division by zero problem. The goal is to catch this error and react accordingly:
CREATE FUNCTION ...
