A(n) join returns not only the rows matching the join condition (that is, rows with matching values in the common columns) but also the rows with unmatched values. a. innerb. crossc. equi-d. outer

outer

Explanation:

JOINs in SQL serve to combine rows of two or more tables based on a common field between them, thus returning data from different tables. A JOIN occurs when two or more tables are joined in an SQL statement.

There are more types of joins in SQL than those explained here, such as CROSS JOIN, OR SELF JOIN, but not all of them are supported by all database systems. The most important are the following:

INNER JOIN: Returns all rows when there is at least one match in both tables.

LEFT JOIN: Returns all rows in the table on the left, and matching rows in the table on the right.

RIGHT JOIN: Returns all rows in the table on the right, and matching rows in the table on the left.

OUTER JOIN: Returns all rows of the two tables, left and right. Also called FULL OUTER JOIN.

OUTER JOIN or FULL OUTER JOIN returns all rows in the table. Combine the result of the LEFT and RIGHT joins. Null will appear in each of the tables alternately when there is no match.

The statement will return all Customers and all Orders, if a customer does not have orders it will show null in OrderID, and if an order did not have a customer it would show null in CustomerName (in this example it would not be logical for an Order not to have a customer).

The syntax of OUTER JOIN or FULL OUTER JOIN does not exist in MySQL, but the same result can be achieved in different ways