Question

Explain Super key, Candidate key & Primary key..
plz.. give proper ans.​

Answer 1

Answer:

• Super key is a single key or a group of multiple keys that can uniquely identify tuples in a table. Super keys can contain redundant attributes that might not be important for identifying tuples.

• A candidate key is a set of attributes (or attribute) which uniquely identify the tuples in relation or table. As we know that Primary key is a minimal super key, so there is one and only one primary key in any relationship but there is more than one candidate key can take place.

• A primary key is the column or columns that contain values that uniquely identify each row in a table. A database table must have a primary key for Optim to insert, update, restore, or delete data from a database table.

Answer 2

Super Key

• A combination of columns that uniquely identifies any row within a relational database management system table.

Candidate Key

• A set of attributes which uniquely identify the tuples in relation or table.

Primary Key

• A key in a relational database that is unique for each record.