What is the primary key answer?

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.

What is primary key class 8 short answer?

Answer: Primary key is a field that uniquely identifies each record in a table. For example, in a school database, the Roll Number of each student uniquely identifies each student. A Primary key does not allow Null Values and must always have a unique value.

What is primary key class 11th?

Primary Key: A candidate key that is primarily chosen for unique identification of tuples in a Relation. Any subset of Primary key should not be Primary key. Alternate Key: Candidate keys that not chosen as primary key are the alternate keys. Example: In a LIBRARY Table.

What is primary key and 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. CUSTOMERS. CustomerNo.

What is primary key Mcq?

Explanation: The primary key is a single or combination of the field that identifies each record in a table uniquely. It cannot take a NULL value. A table can have only one primary key.

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