Features like stored procedures, triggers, referential integrity, and SQL unions and subqueries which are there in relational databases are not supported by MySQL. So there are limitations to the environment in which it can be used. But, it is well suited for Web applications.
Recently, MySQL added support for transactions; they are apparently at work now on stored procedures. That is why MySQL is an excellent product and getting better all the time.
Click on the Link given below to More Details: