When running raw SQL queries in Django you must include a primary key otherwise an invalid query exception is raised. Normally this is fine but when running more complex queries a primary key may not be available or even make sense. There is a simple ...

If you run into this error when trying to create a user in mysql, chances are you already have this user account created. create user 'someuser'@'localhost' identified by 'somepassword'; ERROR 1396 (HY000): Operation CREATE USER failed for 'someuser...

If you follow the instructions on how to install the Rails Redmine PM Software (available here) and are using Apache with Passenger (REE), you need to delete the .htaccess file that is kept in RAILS_ROOT/public directory. Otherwise you'll see a 404 page n...

You might use the attr_accessible method to create getters and setters for a class that has attributes which don't map directly to corresponding fields in a database. For example let's take the scenario where you are processing a credit card transaction. ...