SQL Exercise: Display ID and price of most expensive product

SQL JOINS: Exercise-25 with Solution

From the following tables write a SQL query to find the most expensive product of each company. Return pro_name, pro_price and com_name.

Sample table: company_mast

COM_ID COM_NAME
------ -------------
    11 Samsung
    12 iBall
    13 Epsion
    14 Zebronics
    15 Asus
    16 Frontech

Sample table: item_mast

 PRO_ID PRO_NAME                       PRO_PRICE    PRO_COM
------- ------------------------- -------------- ----------
    101 Mother Board                    3200.00         15
    102 Key Board                        450.00         16
    103 ZIP drive                        250.00         14
    104 Speaker                          550.00         16
    105 Monitor                         5000.00         11
    106 DVD drive                        900.00         12
    107 CD drive                         800.00         12
    108 Printer                         2600.00         13
    109 Refill cartridge                 350.00         13
    110 Mouse                            250.00         12

Sample Solution:

-- Selecting specific columns from the result of an inner join between 'item_mast' and 'company_mast' tables
SELECT A.pro_name, A.pro_price, F.com_name
-- Specifying the tables to retrieve data from ('item_mast' as 'A' and 'company_mast' as 'F')
FROM item_mast A 
-- Performing an inner join based on the equality of 'pro_com' in 'item_mast' and 'com_id' in 'company_mast'
INNER JOIN company_mast F
ON A.pro_com = F.com_id
-- Adding additional conditions to the join, ensuring the 'pro_price' matches the maximum 'pro_price' for the corresponding company
AND A.pro_price =
   (
     -- Subquery: Selecting the maximum 'pro_price' for the current company
     SELECT MAX(A.pro_price)
     FROM item_mast A
     WHERE A.pro_com = F.com_id
   );

Output of the Query:

pro_name	pro_price	com_name
Monitor		5000.00		Samsung
DVD drive	900.00		iBall
Printer		2600.00		Epsion
ZIP drive	250.00		Zebronics
Mother Board	3200.00		Asus
Speaker		550.00		Frontech

Explanation:

The said SQL query is selecting the product name (A.pro_name), product price (A.pro_price) and the company name (F.com_name) of an item, by joining the item_mast table A and company_mast table F on the pro_com column of the item_mast table and the com_id column of the company_mast table. It is also using a subquery to find the highest price of item of the same company, and then join it with the outer query to show the product name, product price, and the company name that has the highest price.

Practice Online

Query Visualization:

Duration:

Rows:

Cost:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous SQL Exercise: Company whose products have an average price.
Next SQL Exercise: Display employees including their department.