Databases are really difficult to update automatically. As I have mentioned somewhere earlier in this book, you will often face customers or database administrators who flat out forbid you to do any updates on a database, let alone do so automatically. It is not uncommon that developers deliver their scripts to a person, typically the DBA, who then manually checks them and runs them on the database. For good reason, the database stores what a business is all about or what it needs to run properly--data. Losing or damaging it can put a company out of business (but, of course, you have backups).
Less severe, but potentially damaging to the business, are scripts that lock tables, update live data, or change business rules. You can imagine that some scripts, such as updating a 1,000 GB table, can potentially lock an entire system. Such updates should happen outside of business...