What is a JOIN? Explain types of JOIN in oracle.

What is a JOIN? Explain types of JOIN in oracle.

Answer
A join is a query that extracts data from two or more tables, views or snapshots.


Types of JOIN

EQUI-JOIN
This is represented by (=) sign. This join retrieves information by using equality condition.
NON-EQUI JOIN

If sign other than =, then it is non-equi join.
SELF JOIN

Self join is a join type between a row of a table to another row of the same table.


OUTER JOIN
This type fetches the row that matches the join condition and rows that don’t match the join condition.

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