What is the method for performing Oracle multi-table joins?

In Oracle, you can perform multi-table join queries using the following methods:

1. Performing a multi-table join query with the WHERE clause: connecting multiple tables by using equal join conditions in the WHERE clause. For example:

SELECT *
FROM table1, table2
WHERE table1.column = table2.column;

1. Performing a multi-table join query using INNER JOIN: By using the INNER JOIN keyword, multiple tables can be linked together, and the connecting conditions are specified in the ON clause. For example:

SELECT *
FROM table1
INNER JOIN table2
ON table1.column = table2.column;

1. Performing a multi-table join query with LEFT JOIN: Connecting multiple tables using the LEFT JOIN keyword and specifying the connection conditions in the ON clause, it will return all records from the left table, even if there are no matching records in the right table. For example:

SELECT *
FROM table1
LEFT JOIN table2
ON table1.column = table2.column;

1. Perform a multi-table join query using RIGHT JOIN: This involves connecting multiple tables using the RIGHT JOIN keyword and specifying the join conditions in the ON clause. It will return all records from the right table, even if there are no matching records in the left table. For example:

SELECT *
FROM table1
RIGHT JOIN table2
ON table1.column = table2.column;

1. Perform a multi-table query using a FULL JOIN: Use the FULL JOIN keyword to connect multiple tables together and specify the connection conditions in the ON clause, returning all records from both the left and right tables. For example:

SELECT *
FROM table1
FULL JOIN table2
ON table1.column = table2.column;

1. Performing a multi-table JOIN using CROSS JOIN: By using the CROSS JOIN keyword, multiple tables are combined to compute the Cartesian product, returning all possible combinations of the two tables. For example:

SELECT *
FROM table1
CROSS JOIN table2;

The join conditions in the above methods can be adjusted and expanded based on actual needs.