SQL Exercises: Customer with the highest purchase amount

SQL Aggregate Functions: Exercise-17 with Solution

From the following table, write a SQL query to determine the maximum order (purchase) amount generated by each salesperson. Filter the rows for the salesperson ID is in the range 5003 and 5008 (Begin and end values are included.). Return salesperson id and maximum purchase amount.

Sample table: orders

ord_no      purch_amt   ord_date    customer_id  salesman_id
----------  ----------  ----------  -----------  -----------
70001       150.5       2012-10-05  3005         5002
70009       270.65      2012-09-10  3001         5005
70002       65.26       2012-10-05  3002         5001
70004       110.5       2012-08-17  3009         5003
70007       948.5       2012-09-10  3005         5002
70005       2400.6      2012-07-27  3007         5001
70008       5760        2012-09-10  3002         5001
70010       1983.43     2012-10-10  3004         5006
70003       2480.4      2012-10-10  3009         5003
70012       250.45      2012-06-27  3008         5002
70011       75.29       2012-08-17  3003         5007
70013       3045.6      2012-04-25  3002         5001

Sample Solution:

-- This query retrieves the maximum 'purch_amt' value for each 'salesman_id' from the 'orders' table.
-- The result set is then filtered to only include rows where the 'salesman_id' is between 5003 and 5008.
SELECT salesman_id, MAX(purch_amt)
-- Specifies the table from which to retrieve the data (in this case, 'orders').
FROM orders
-- Groups the result set by the 'salesman_id' column.
GROUP BY salesman_id
-- Filters the grouped results to only include rows where the 'salesman_id' is between 5003 and 5008.
HAVING salesman_id BETWEEN 5003 AND 5008;

Output of the Query:

salesman_id	max
5005		270.65
5003		2480.40
5007		75.29
5006		1983.43

Code Explanation:

In the given SQL query, the salesman_id and the maximum purchase amount (purch_amt) will be retrieved from the 'orders' table for salesmen with an id between 5003 and 5008.
The result will show the maximum purchase amount made by each salesman in the specified range. The "HAVING" clause filters the result set by only showing salesmen whose id is between 5003 and 5008.
The result will show the maximum purchase amount made by each salesman, with the salesman_id being grouped together.

Explanation:

Visual presentation:

Practice Online

Query Visualization:

Duration:

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Previous SQL Exercise: Customer details and purchases over a certain amount.
Next SQL Exercise: Count all orders for a specific date.