Fun With Postgres: Custom Constraints
Postgres comes with a rich set of tool to help developers maintain data integrity. Many of them come in the form of Constraints. Foreign Key, Not Null, Exclusion, and Check constraint allow developers to off load what would usually be a lot of application code to the database server with very litte effort.
Between the Foreign key, which verifies values in another table, and the Check constraint, which verifies values in a specific column, you can typically accomplish just about everything you need to do rather easily. The main problem the you'll run into is that these kinds of constraints are restricted to a single column on a table. Additionally they only apply the the current value in thatRead More