Aug 04, 2020 11:09 am
SQL Constraints
1 Reply
Aug 05, 2020 4:07 am
SQL constraints are the set of rules that impose some restrictions while insertion, deletion, or updating of data in the databases.
In SQL we have both column level as well as table level constraints which are applied at columns and tables respectively. Some of the constraints in SQL are as follows.
- Primary Key
- Foreign Key
- Unique Key
- Not NULL
- DEFAULT
- CHECK
- Index