Key constraints in dbms: A database is a collection of data organized in a specific way. A database management system (DBMS) allows you to create and manage databases. You need to be aware of three key constraints primary key, foreign key, and unique key. Each constraint has a specific purpose, and it is important to understand how they work to create efficient databases. Let’s take a closer look at each one!
The primary key constraint is used to identify a record in a table. The primary key must be unique and cannot contain null values. In other words, it is the key that is used to identify a row in a table uniquely.
The foreign key constraint links two tables together. It ensures that the data in one table matches the data in another. The foreign key can be either a primary key or a unique key.
The unique key constraint ensures that no two records in a table have the same value for a given column. This constraint is similar to the primary key constraint, but the key doesn’t need to be unique.
Each of these constraints plays an important role in maintaining the data integrity in a database. They are key to preventing accidental data corruption and ensuring that the data in the database is consistent and accurate.