Counting Records with SQL

This challenge focuses on using the COUNT aggregate function in SQL. Understanding how to count records is fundamental for data analysis, allowing you to quickly gauge the size of datasets and identify patterns.

Problem Description

You are provided with two database tables: Customers and Orders. Your task is to write an SQL query that counts the total number of orders placed by all customers.

Requirements:

• The query should return a single value representing the total count of orders.
• You must use the COUNT() aggregate function.

Expected Behavior: The query should sum up all individual order records from the Orders table.

Edge Cases:

• If there are no orders in the Orders table, the count should be 0.

Examples

Example 1:

Input Tables:

Customers

Orders

Output:

TotalOrders
-----------
3

Explanation: There are 3 records in the Orders table, so the total count of orders is 3.

Example 2:

Input Tables:

Customers

Orders

Output:

TotalOrders
-----------
1

Explanation: There is 1 record in the Orders table, so the total count of orders is 1.

Example 3: (Edge Case)

Input Tables:

Customers

Orders

Output:

TotalOrders
-----------
0

Explanation: The Orders table is empty, therefore the count of orders is 0.

Constraints

• The Orders table can contain between 0 and 1,000,000 records.
• Table names are Customers and Orders.
• Assume valid SQL syntax is used.
• The query should be efficient and execute within reasonable time limits for the given data size.

Notes

• You do not need to join the Customers table for this specific problem. The COUNT function can be applied directly to the Orders table.
• Consider what you should count within the COUNT() function to get the total number of rows.