Question

The outer join operator is placed on the side of the joining condition that references the table containing the deficient rows. _________________________

a) LEFT JOIN
b) RIGHT JOIN
c) FULL JOIN
d) CROSS JOIN

Answer 1

The join operator referenced is a LEFT JOIN, which is used in SQL to ensure that all rows from the first (left) table are included in the results, even if there are no corresponding rows in the second (right) table.

Step-by-step explanation:

The outer join operator is used in SQL to combine rows from two or more tables. The specific type of outer join that places the operator on the side of the joining condition referencing the table with potentially missing data is the LEFT JOIN. For example, if you have a table of customers and a table of orders, and you want to see all customers and their corresponding order details (including those customers who have not placed any orders), you would use a LEFT JOIN. The LEFT JOIN ensures that all rows from the 'left' table (the customer table, in this scenario) are included in the result set, even if there are no matching rows in the 'right' table (the orders table). On the other hand, RIGHT JOIN is similar but includes all rows from the 'right' table. FULL JOIN combines the effects of both LEFT and RIGHT joins, including all rows from both tables, and CROSS JOIN generates a Cartesian product between tables, unrelated to outer joins.