Which key can be primary key?

Question

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.

Can a candidate key be a primary key?

Each Candidate Key can qualify as Primary Key. Primary Key – A Primary Key is a column or a combination of columns that uniquely identify a record. Only one Candidate Key can be Primary Key. A CK is a set of columns that is unique and does not contain a smaller set of columns that is unique.

Can there be 2 primary key?

A table can have only ONE primary key; and in the table, this primary key can consist of single or multiple columns (fields).

Expert · Answer

Each Candidate Key can qualify as Primary Key. Primary Key – A Primary Key is a column or a combination of columns that uniquely identify a record. Only one Candidate Key can be Primary Key. A CK is a set of columns that is unique and does not contain a smaller set of columns that is unique.

Expert · Answer

A table can have only ONE primary key; and in the table, this primary key can consist of single or multiple columns (fields).

Which key can be primary key?

Can a candidate key be a primary key?

Can there be 2 primary key?

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