What is primary key and secondary?

What is a secondary key example?

Let's say you selected Student_ID as primary key, therefore Student_Enroll and Student_Email will be Secondary Key (candidates of primary key).

What is a primary key with example?

A primary key is a column -- or a group of columns -- in a table that uniquely identifies the rows of data in that table. For example, in the table below, CustomerNo, which displays the ID number assigned to different customers, is the primary key.

What is the primary key?

A primary key, also called a primary keyword, is a key in a relational database that is unique for each record. It is a unique identifier, such as a driver license number, telephone number (including area code), or vehicle identification number (VIN). A relational database must always have one and only one primary key.

What is key and primary key?

Primary Key is a column that is used to uniquely identify each tuple of the table. ... Difference between Primary Key and Unique Key.Primary KeyUnique KeyOnly one primary key can be present in a tableMultiple Unique Keys can be present in a table