What is Join? | Eklavya Online

What is Join?

he Join operation is one of the most useful activities in relational algebra. It is most commonly used way to combine information from two or more relations. A Join is always performed on the basis of the same or related column. Most complex queries of SQL involve JOIN command.

There are following types of join:

Inner joins: Inner join is of 3 categories. They are:

  • Theta join
  • Natural join
  • Equi join

Outer joins: Outer join have three types. They are:

  • Left outer join
  • Right outer join
  • Full outer join