There is a mistake in the article, due to the OP not knowing an arguably basic notion about MySQL.

> when defining a field as int(11) you can just happily insert textual data and MySQL will try to convert it.

this is dependent on the SQL Mode, which is quite flexible. for example, the STRICT_ALL_TABLES will prevent strings to be inserted in INT fields:

mysql> create table example ( `number` int(11) not null );

mysql> insert into example (number) values ('wat'); Query OK, 1 row affected, 1 warning (0,00 sec)

mysql> SET sql_mode = 'STRICT_ALL_TABLES';

mysql> insert into example (number) values ('wat'); ERROR 1366 (HY000): Incorrect integer value: 'wat' for column 'number' at row 1

There are certainly advantages in choosing PostgreSQL over MySQL... this is just not one of them :-)