What is Conditional Summation
Conditional summation is a type of calculation that involves the summation of data values from a particular dataset using certain conditions or criteria as a basis. SUM() function along with the CASE statement enables us to accomplish the task for PostgreSQL. The CASE statement is the conditional one, which sets up the conditions and returns the result of the first condition that is true.
Syntax:
The syntax for conditional summation in PostgreSQL can be summarized as follows:
SELECT SUM(CASE
WHEN condition1 THEN value1
WHEN condition2 THEN value2
...
ELSE default_value
END) AS sum_result
FROM table_name;
In this syntax:
- condition1, condition2, etc., represent the conditions to be evaluated.
- value1, value2, etc., represent the values to be summed if the corresponding condition is true.
- default_value is the value returned if none of the conditions are met.
- table_name is the name of the table from which data is being retrieved.
Now let’s start by creating a table and inserting some sample data into it. We’ll then proceed to demonstrate some example queries for conditional summation in PostgreSQL.
Create a table named sales and insert some data into it.
CREATE TABLE sales (
product_id SERIAL PRIMARY KEY,
quantity_sold INTEGER,
unit_price NUMERIC,
category VARCHAR(50)
);
INSERT INTO sales (quantity_sold, unit_price, category) VALUES
(10, 15.50, 'Electronics'),
(5, 20.25, 'Electronics'),
(8, 10.75, 'Clothing'),
(15, 7.99, 'Clothing'),
(20, 5.50, 'Home Appliances'),
(10, 12.75, 'Home Appliances');
Output:
You can see the table content below:
Conditional Summation in PostgreSQL
PostgreSQL is a powerful tool that includes advanced features in the field of data analysis and database management. One of its significant useful functions is the capacity to carry out conditional summation, which allows users to add up numbers based on given conditions.
This article goes through the concept of conditional summation in PostgreSQL, illustrating its usage and providing practical examples.