Using the customers table, you need to generate a report that shows 50% of each credit
amount in each income level. The report should NOT show any repeated credit amounts in
each income level. Which query would give the required result?
A.
Option A
B.
Option B
C.
Option C
D.
Option D
Explanation:
Duplicate Rows
Unless you indicate otherwise, SQL displays the results of a query without eliminating the
duplicate rows. To eliminate duplicate rows in the result, include the DISTINCT keyword in
the SELECT clause immediately after the SELECT keyword.
You can specify multiple columns after the DISTINCT qualifier. The DISTINCT qualifier
affects all the selected columns, and the result is every distinct combination of the columns.