![](https://www.opentextbooks.org.hk/sites/opentextbooks/files/book_profile/cc_icon/by-sa.png)
Available under Creative Commons-ShareAlike 4.0 International License.
Constraints are a very important feature in a relational model. In fact, the relational model supports well defined theory of constraints on attributes or tables. Constraints are useful because they allow a designer to specify the semantics of data in the database and constraints are the rules to enforce DBMSs to check that data satisfies the semantics.
- 2520 reads