MySQL SUM() Function

 The SUM() function in MySQL is an aggregate function that is used to calculate the total sum of a numeric column. It can be useful when you want to get the sum of values in a column, often combined with GROUP BY to summarize data by different categories.

Syntax:

SELECT SUM(column_name)
FROM table_name
WHERE condition;

• column_name: The name of the numeric column whose values you want to sum.
• table_name: The name of the table containing the column.
• condition: An optional WHERE clause to filter rows that will be summed.

Example 1: Basic SUM() Usage

To get the total sales from a sales table:

SELECT SUM(sale_amount) AS total_sales
FROM sales;

Example 2: SUM() with GROUP BY

If you want to calculate the total sales for each product category:

SELECT category, SUM(sale_amount) AS total_sales
FROM sales
GROUP BY category;

Example 3: Using SUM() with a WHERE clause

If you want to sum sales for a specific period (e.g., for 2024):

SELECT SUM(sale_amount) AS total_sales
FROM sales
WHERE YEAR(sale_date) = 2024;

Notes:

• SUM() ignores NULL values.
• It can only be used with numeric columns or expressions.

Let me know if you'd like further examples!