Join is a query that is used to combine rows from two or more tables, views, or materialized views. It retrieves data from multiple tables and creates a new table.
Join Conditions
There may be at least one join condition either in the FROM clause or in the WHERE clause for joining two tables. It compares two columns from different tables and combines pair of rows, each containing one row from each table, for which join condition is true.
Types of Joins
- Inner Joins (Simple Join)
- Outer Joins
- Left Outer Join (Left Join)
- Right Outer Join (Right Join)
- Full Outer Join (Full Join)
- Equijoins
- Self Joins
- Cross Joins (Cartesian Products)
- Antijoins
- Semijoins
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