What is primary key class?

Question

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.

What is a primary key class 8?

A Primary key is a check on the table that uniquely identifies each record on a table. It does not contain any duplicate data. A table can have only one Primary key.

What is primary key short answer?

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 a primary key class 11?

The primary key is the minimum set of traits that distinguishes any row of a table. It cannot have NULL and duplicate values. The primary key is used to add integrity to the table. In the case of a primary key, both Duplicate and NULL values are not valid. And, it can be utilized as foreign keys for different tables.

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.

Expert · Answer