Question

Write a SELECT statement that returns these column names and data from the Products table: product_name The product_name column list_price The list_price column discount_percent The discount_percent column discount_amount A column that’s calculated from the previous two columns discount_price A column that’s calculated from the previous three columns Round the discount_amount and discount_price columns to 2 decimal places. Sort the result set by the discount_price column in descending sequence. Use the LIMIT clause so the result set contains only the first 5 rows.

Answer 1

Answer:

 SELECT  

   product_name, list_price, discount_percent,    

   ROUND(list_price * (discount_percent / 100), 2) AS discount_amount,

   ROUND(list_price - (discount_percent / 100 * list_price), 2)  AS discount_price  

FROM

Products

ORDER BY (list_price - (discount_percent / 100 * list_price)) DESC

LIMIT 5;

Explanation:

In the above SELECT statement is used to select columns from Products table.

The columns are  product_name,list_price and discount_percent

Next a column discount_amount is selected which is the calculated from previous two columns that are list_price and discount_percent. The discount amount is basically calculated by multiplying list_price with discount_percent/100 and the resultant column is named as discount_amount using Alias which is used to give a temporary name to set of columns or a table.

Next another column discount_price is obtained from previous three columns that are  list_price , discount_percent and discount_amount as: list_price - (discount_percent / 100 * list_price) This as a whole is given a column name discount_price.

FROM is used to refer to a table from which these columns are to be selected. The table name is Product.

The result set is sorted in descending order by discount_price so ORDER BY is used to order the resultant records and DESC is used to sort these records according to the discount_price in descending order.

LIMIT statement is used to extract the records from Product and limit the number of rows returned as a result based on a limit value which is 5 here.