What is the difference between the COUNT() function and the SUM() function in SQL?
What is the difference between the COUNT() function and the SUM() function in SQL?
Ask by Revati S Misra
Updated 18 Nov 2023
In SQL, the COUNT and SUM functions serve different purposes and are used for different types of calculations.
COUNT Function:
The COUNT function is used to count the number of rows in a result set or the number of occurrences of a particular value in a column. It is often used in combination with the GROUP BY clause to get counts for groups of data.
Syntax:
Example:
SUM Function:
The SUM function, on the other hand, is used to calculate the sum of numerical values in a column. It adds up the numeric values in the specified column.
Syntax:
Example:
Key Differences:
Purpose:
Data Type:
Usage:
NULL Handling:
Example:
In this example, we are using both COUNT and SUM to get the count of employees and the total salary in a single query.