SQL – Alternate Key Table of content The SQL Alternate Key SQL Alternate Keys in a database table are candidate keys that are not currently selected as a primary key. They can be used to uniquely identify a tuple(or a record) in a table. There is no specific query or syntax to set the alternate […]

SQL – Composite Key Table of content The SQL Composite Key An SQL Composite Key is a key that can be defined on two or more columns in a table to uniquely identify any record. It can also be described as a Primary Key created on multiple columns. Composite Keys are necessary in scenarios where […]

SQL – Primary Key Table of content The SQL Primary Key The SQL Primary Key is a column (or combination of columns) that uniquely identifies each record in a database table. The Primary Key also speeds up data access and is used to establish a relationship between tables. Even though a table can only have […]