Asked by: Mata Molano
asked in category: General Last Updated: 11th March, 2020

What is the point of a self join?

You use a self join when a table references data in itself. E.g., an Employee table may have a SupervisorID column that points to the employee that is the boss of the current employee. It's basically used where there is any relationship between rows stored in the same table.

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Similarly, what is the purpose of self join?

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.

Likewise, what is the use of self join in Oracle with example? A self join is a join that joins a table with itself. A self join is useful for comparing rows within a table or querying hierarchical data. A self join uses other joins such as inner join and left join. In addition, it uses the table alias to assign the table different names in the same query.

Correspondingly, what is self join with example?

A self JOIN occurs when a table takes a 'selfie'. A self JOIN is a regular join but the table is joined with itself. This can be useful when modeling hierarchies. They are also useful for comparisons within a table.

Is self join and inner join are same?

The main difference between Self Join and Equi Join is that In Self Join we join one table to itself rather than joining two tables. Both Self Join and Equi Join are types of INNER Join in SQL, but there is the subtle difference between two. Any INNER Join with equal as join predicate is known as Equi Join.

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