Introduction to Database Keys
In this lesson, we will highlight some of keys that are present in databases.
We'll cover the following...
Keys are a very important part of the relational database model. They are used to establish and identify relationships between tables and also to uniquely identify any record or row of data inside a table.
A key can be a single attribute or a group of attributes, where the combination may act as a key.
Why do we need a key?
In real-world applications, the number of tables required for storing data is huge, and different tables are related to each other as well.
Also, tables store a lot of data. Tables generally extend to thousands of records, unsorted and unorganized.
Now, to fetch any particular record from such a dataset, you will have to apply some conditions. But what if there is duplicate data present and every time ...