SQL Exercises: Find the average purchase amount of all orders

SQL Aggregate Functions: Exercise-2 with Solution

From the following table, write a SQL query to calculate the average purchase amount of all orders. Return average purchase amount.

Sample table: orders

Sample Solution:

SELECT AVG (purch_amt) 
FROM orders;

Output of the Query:

avg
1461.7650000000000000

Code Explanation:

The said SQL query retrieves the average of values in the "purch_amt" column from the 'orders' table. The "SELECT AVG (purch_amt)" statement specifies that the average of the values in the "purch_amt" column should be retrieved. The result of this query will be a single value that represents the average of all values in the "purch_amt" column in the 'orders' table.

Relational Algebra Expression:

Relational Algebra Tree:

Explanation:

visual presentation :

Practice Online

Query Visualization:

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