Lately, i needed to deal with the following scenario: read from two databases (db1,db2), and write to a third database (db3).

This method allows to log InnoDB monitor output when deadlock error occured. This way we will have much more useful data to find and fix deadlock.

Suppose to have two models: Users and Emails. You do not want to store email in a Users model. And User can have 0 or many emails. This is the form generated to create a new user (just username).

I like programing on my localhost, however it really bugged me to make changes to index.php & config files on my production server. After combining all available wiki articles on this topic and some trial and error this is what I use for my applications so I could just upload it to production server and it will work without any changes.

Virtually all Yii applications are built on top of a database, and though Yii is very flexible in how it addresses your DB, some design choices make things more convenient than others.

What would you do if you want/need to have a different than the main database connection in an module's models?

To get null from database instead of empty strings you need to set up your DB connection as follows: