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.