Postgres List Constraints

A constraint is a set of rules that followed by tables in a database of the PostgreSQL to prevent invalid data structure of data being entering into the tables of the database.

Constraints classified based on the columns and table levels.

Constraints are responsible for the clarity, reliability, accuracy of the data stored in the database.

There are many types of Constraints as some of the most used are like:

1. UNIQUE Constraint
2. NOT NULL Constraint
3. PRIMARY KEY Constraint
4. FOREIGN KEY Constraint
5. DROPPING Constraint
6. CHECK Constraint and EXCLUSION Constraint