Sure! Here are the main types of SQL JOINs used to combine rows from two or more tables based on related columns:

1. INNER JOIN

• Returns only the rows where there is a match in both tables.

• Rows without matching values in either table are excluded.

SELECT columnsFROM table1INNER JOIN table2ON table1.common_column = table2.common_column;

2. LEFT JOIN (or LEFT OUTER JOIN)

• Returns all rows from the left table and matched rows from the right table.

• If there is no match, the result contains NULL for right table columns.

SELECT columnsFROM table1LEFT JOIN table2ON table1.common_column = table2.common_column;

3. RIGHT JOIN (or RIGHT OUTER JOIN)

• Returns all rows from the right table and matched rows from the left table.

• If no match, NULL values for left table columns.

SELECT columnsFROM table1RIGHT JOIN table2ON table1.common_column = table2.common_column;

4. FULL JOIN (or FULL OUTER JOIN)

• Returns rows when there is a match in either left or right table.

• Non-matching rows from both sides are included with NULLs for missing parts.

SELECT columnsFROM table1FULL OUTER JOIN table2ON table1.common_column = table2.common_column;

5. CROSS JOIN

• Returns the Cartesian product of both tables.

• Combines every row of the first table with every row of the second table.

• No ON clause needed.

SELECT columnsFROM table1CROSS JOIN table2;

6. SELF JOIN

• A join where a table is joined with itself.

• Useful for hierarchical or comparative queries.

SELECT a.columns, b.columnsFROM table1 aJOIN table1 bON a.common_column = b.related_column;

Summary Table

If you want, I can provide example queries for any join type!