First of all, I want to thank you for all of the resources provided by w3schools. My colleagues and I use the site every day. Please keep it up, and THANK YOU!!!

I have a suggestion for content that may be helpful for others:

SQL:FOREIGN KEYS

MySQL's default engine, MyISAM, does not support foreign keys. A query with the proper syntax will succeed with no error message generated, but MySQL will not enforce referential integrity. (For example, it mysteriously allows the addition of a record to table1 with a FK value that does not exist as a PK in table2).

Of course there are other considerations to engine selection, but this issue may be useful for others to discover on this page of the SQL tutorial: http://www.w3schools.com/sql/sql_foreignkey.asp.

The solution I chose to use was to convert my tables to InnoDB. Perhaps you can phrase this more eloquently, but I hope it is helpful!

Thanks again!