Explain Constraints in SQL?
It is a rule used to limit the type of data that can insert into a table, to maintain the integrity and accuracy of the data inside the table.
It can be divided into two types.
- Column level constraints
- Table-level constraints
These are the most common constraints that can be applied to a table.
- NOT NULL
- PRIMARY KEY
- FOREIGN KEY etc
BY Best Interview Question ON 27 Jan 2019