Constraints in SQL

Introduction

SQL constraints are a collection of rules used on tables in relational databases to limit the types of data that may be added, changed, or removed from those tables. By doing this, the information recorded in the table is guaranteed to be reliable and accurate. After the constraint is set up, any database operation that doesn't adhere to the restrictions set forth by the constraint is terminated. We will discuss SQL constraints in this post, including what they are, the many types that are frequently used, how to apply them, and how to remove them. But first, let's quickly go through the main benefits of constraints.