Question

A self join can be used when there are two.Fields with the same.Data on a table that have different meanings

Answer 1

Answer:

Summary: in this tutorial, you will learn how to use the SQL Server self join to join a table to itself.

SQL Server self join syntax

A self join allows you to join a table to itself. It is useful for querying hierarchical data or comparing rows within the same table.

A self join uses the inner join or left join clause. Because the query that uses self join references the same table, the table alias is used to assign different names to the same table within the query.

Note that referencing the same table more than one in a query without using table aliases will result in an error.

The following shows the syntax of joining the table T to itself: