Should data validation be done at the database level?

Question

I am writing some stored procedures to create tables and add data. One of the fields is a column that indicates percentage. The value there should be 0-100. I started thinkin

Answer 1

In a perfect world the only thing talking (updating, deleting, inserting) to your database would be your business api. In the perfect world databae level constraints are a waste of time, your data would already have been validated and cross checked in your business api. In the real world we get cowboys taking shortcuts and other people writing directly to the database. In this case some constraints on the database are well worth the effort. However if you have people not using your api to read/write you have to consider where you went wrong in your api design.