MCQ IN COMPUTER SCIENCE & ENGINEERING

Detailed explanation-1: -A primary key consists of one or more fields that uniquely identify each record that you store in the table. Often, there is a unique identification number, such as an ID number, a serial number, or a code, that serves as a primary key.

Detailed explanation-2: -A primary key is used to uniquely identify a record in a table, while a candidate key helps in selecting the primary key. Another key difference between a primary key and a candidate key is that a table can have only one primary key, but there can be multiple candidate keys.

Detailed explanation-3: -A Super Key is simply a non-minimal Candidate Key, that is to say one with additional columns not strictly required to ensure uniqueness of the row. A Primary Key is a minimal Candidate Key, which is to say all constituent columns are strictly required in order to ensure uniqueness.

Detailed explanation-4: -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.

Detailed explanation-5: -A primary key is a column of table which uniquely identifies each tuple (row) in that table.