More videos like this at www.theurbanpenguin.com So we have looked at installing MySQL on SLE 11. So now we need a database and tables. We will also add Primary and Foreign Key constraints to the tables. Primary Keys ensure uniqueness of a column values within a table sot hat the row can re identified and Foreign keys ensure integrity by allowing values to be added that exist in another table. For example an employee can only be added to a department that exists.