Self Join

A self join is a query in SQL that joins a table to itself. This is useful when you want to compare rows within the same table, often based on a hierarchical relationship or other connection between the data points within that table. Think of it as creating two copies of the same table and then joining them based on a shared column, allowing you to relate data from the same source in a new way.

Visit the following resources to learn more:

• @article@Understanding the Self Joins in SQL
• @article@SQL self joins