Purpose

Associates multiple tables within a Select statement. Joins may be either explicit or implicit.

Example A

This is the example from the previous section restated as an explicit inner join:

SELECT e.name, d.deptName 
FROM emp e INNER JOIN dep d ON e.deptId = d.id;
FROM table_name {RIGHT OUTER | INNER | LEFT OUTER | CROSS} JOIN table.key ON search-condition

Example B

In this example, two tables are joined using LEFT OUTER JOIN. T1, the first table named includes nonmatching rows.

SELECT * FROM T1 LEFT OUTER JOIN T2 ON T1.key = T2.key

If you use a CROSS JOIN, no ON expression is allowed for the join.