When a Database is in a THEN statement, the game creates that database when it is reached. Databases can be created and values added (or removed) mid-game, which is one of the few ways for different functions to communicate with each other.
In svansted's example, DB_AllInTrigger(1) is creating a new database with an Integer entry of 1. The next part of the code then removes this flag if an item is not within the trigger area (by using NOT DB_AllInTrigger(1); in the THEN statement). Finally the last part checks whether the Database still exists, and displays the result if so.
