Question

Using Oracle Proprietary join syntax, which operator would you use after one of the column names in the WHERE clause when creating an outer join?

A.(+)
B.=
C.+
D.*

Answer 1

In Oracle Proprietary join syntax, the operator used after a column name in the WHERE clause to create an outer join is (A.(+)). This allows for rows without a matching row in another table to be included in the query results.

Step-by-step explanation:

When using Oracle Proprietary join syntax to create an outer join in a WHERE clause, the operator that should be used after one of the column names is (+). This operator indicates that the join is an outer join, which allows for the inclusion of rows that do not have a matching row in the other table. For example, if you want to retrieve all rows from the table employees and any corresponding rows from the departments table, you would use the following query:

SELECT e.name, d department_name
FROM employees e, departments d
WHERE d department_id = d department_id(+);

In this query, d department_id is equated with d department_id and the (+) operator is used to perform a left outer join. This ensures that even if some employees do not belong to a department, they will still be listed in the result with a NULL value for the department_name.