SQL Joins Clearly Explained

Left Join

Returns all records from the left table (A) and the matched records from the right table (B). If there’s no match, it returns NULL on the right side.

Keeps all records from A and fills in matching data from B.

Left Join Without Overlapping

Returns all records from A that don’t have a match in B.

Ideal for finding exclusive entries in A that aren’t in B.

Right Join

Opposite of Left Join—returns all records from B and matched records from A. If there’s no match, it returns NULL on the left side.

Focuses on B and brings in data from A where available.

Right Join Without Overlapping

Returns all records from B that don’t have a match in A.

Perfect for spotting unique entries in B.

Full Join

Combines results of Left Join and Right Join, returning all records when there is a match in either A or B.

Use this for a complete view of both tables.

Inner Join

Returns only records that have matching values in both tables.

Best for retrieving intersecting data between A and B.

Full Join Without Overlapping

Returns all records from A and B where there is no match in the other table.

Use this to see what’s missing in both A and B. Great for identifying data gaps.

Master SQL Joins for Better Database Queries!

Credit by: Josep Ferrer