What is a primary key? A primary key is a column or columns in a database table with values that uniquely identify each row or record. For example, an employee ID column could be a primary …

Nov 15, 2025 · Primary Key: A primary key is a type of key that contains a column or set of columns in a table that uniquely identifies each row in the table. The primary key is an attribute …

Jan 3, 2025 · Among the various types of keys utilized in database management, the primary key holds significant importance. It acts as a unique identifier for each record in a database table, …

SQL PRIMARY KEY Constraint The PRIMARY KEY constraint is used to uniquely identify each record in a table. Primary keys must contain unique values, and cannot contain NULL values. …

Oct 25, 2022 · A primary key, also called a primary keyword, is a column in a relational database table that's distinctive for each record. It's a unique identifier, such as a driver's license …

Jun 18, 2024 · A primary key is a column, or a set of columns, in a database table that uniquely identifies each row in that table. The primary key must contain unique values and cannot …

May 24, 2016 · A primary key is one or more columns that have been configured as the unique identifier field for the table. Most primary keys are comprised of a single column, but they can …

Aug 7, 2025 · A primary key is a constraint that uniquely identifies each record in a table, acting as a foundational element for indexing, enforcing entity integrity, and establishing relationships …

Jun 16, 2025 · The primary key (PK) is a cornerstone concept in relational database management systems (RDBMS) and plays a pivotal role in ensuring data integrity, facilitating efficient data …

In the relational model of databases, a primary key is a designated set of attributes (column (s)) that can reliably identify and distinguish between each individual record in a table.