Question

The ID column in the CLIENT table that corresponds to the CLIENT_ID column of the ORDER table contains null values for rows that need to be displayed. Which type of join should you use to display the data?

a.Self join
b.Nonequi-Join
c.Outer join
d.Equijoin

Answer 1

To display all rows from the CLIENT table with or without matching rows in the ORDER table, an outer join should be used. This allows inclusion of clients who have not placed any orders, by showing nulls where no matching data exists.

Step-by-step explanation:

If you need to display rows from the CLIENT table, including those that do not have a corresponding entry in the ORDER table (i.e., rows with null values in the ID column that corresponds to the CLIENT_ID column of the ORDER table), you should use an outer join.

An outer join ensures that all rows from the specified side of the join (left, right, or full) will appear in the result set, even if there is no matching row in the joined table. In this case, if you want to include all clients regardless of whether they have placed an order, a left outer join from the CLIENT table to the ORDER table would be appropriate. This will include all CLIENT entries and the matching ORDER entries where available.