SQL SUM() Function

The SQL SUM() function is an aggregate function used to calculate the sum of values in a specified column of a table. It is commonly used in conjunction with the SELECT statement to perform calculations on numeric data. Here’s the basic syntax of the SUM() function:

• column_name: The name of the column for which you want to calculate the sum.
• table_name: The name of the table from which you want to retrieve data.
• condition: An optional condition to filter the rows before calculating the sum.

The SUM() function adds up all the values in the specified column. If a condition is provided, it filters the rows before performing the sum calculation.

Here’s an example using a fictional table named sales:

id	region	sale_amount
1	North	100.52
2	South	123.85
3	South	456.12
4	North	321.23

Now, let’s calculate the total sale amount:

This would produce the result:

+————————-+
| SUM(sale_amount)|
+————————–+
|1001.72
+—————————+

In this example, the SUM() function adds up all the values in the sale_amount column of the sales table, resulting in a total sale amount of 526.50.

You can also use the SUM() function with the GROUP BY clause to calculate sums for each group based on a specific column, as demonstrated in the previous response.

Now, let’s calculate the total sales for each region:

This would produce the following result:

+——–+———————-+
| region | SUM(amount) |
+——–+———————-+
| North | 421.75|
| South | 579.97|
+——–+———————-+

This result shows the total sales for each region based on the data in the sales table.