SQL Exercises: Find the maximum purchase amount of all the orders

SQL Aggregate Functions: Exercise-6 with Solution

From the following table, write a SQL query to find the 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 value in the 'purch_amt' column from the 'orders' table.
SELECT MAX(purch_amt)
-- Specifies the table from which to retrieve the data (in this case, 'orders').
FROM orders;

Output of the Query:

max
5760.00

Code Explanation:

The said SQL statement is used to retrieve the highest value in the "purch_amt" column from the 'orders' table. The "MAX" function is used to find the maximum value in the specified column.
The result of the query would be a single value representing the highest "purch_amt" in the 'orders' table.

Relational Algebra Expression:

Relational Algebra Tree:

Explanation:

Visual presentation:

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