Mysql: adding foreign key does not give warning/error on MyISAM tables

Question

Here is a table I made:

mysql> show create table notes;
+-------+----------------------------------------------------+
| Table | Create Table                      


        

Answer 1

myISAM doesn't do referential integrity. it seems it is legal to add such constraints and hence no error, though the constraints won't be enforced as long as the engine is myISAM. It does store the keys created so the user can see what was intended, though.