MySQL WHERE SUM > 0 - SQL

Introduction

As a programmer, you may often work with databases and SQL queries. One common task is to retrieve data that meets certain conditions, such as a sum greater than zero. In this article, we will explore how to use the WHERE clause in MySQL to filter results based on the sum of a column.

Example Data

To illustrate the use of WHERE SUM > 0 in MySQL, we will use a sample table that contains sales data for a fictional company. The table is named sales and has the following columns:

• id: unique identifier for each sale
• product: name of the product sold
• price: sale price of the product
• quantity: number of units sold

CREATE TABLE sales (
  id INT UNSIGNED NOT NULL AUTO_INCREMENT,
  product VARCHAR(50) NOT NULL,
  price DECIMAL(10, 2) NOT NULL,
  quantity INT UNSIGNED NOT NULL,
  PRIMARY KEY (id)
);

INSERT INTO sales (product, price, quantity) VALUES
('Product A', 10.00, 5),
('Product B', 20.00, 2),
('Product C', 15.00, 0),
('Product D', 5.00, 10),
('Product E', 25.00, 3);

SQL Syntax

To filter the results based on the sum of a column in MySQL, we can use the HAVING clause along with the SUM function. Here's the basic syntax:

SELECT column1, column2, SUM(column3) as total
FROM table_name
WHERE condition
GROUP BY column1, column2
HAVING total > 0;

In this syntax, column1 and column2 are the columns that we want to retrieve data from, and column3 is the column whose sum we want to filter on. table_name is the name of the table that contains the data. The WHERE clause is used to apply a filter on the data before grouping, and the GROUP BY clause is used to group the data by one or more columns. The SUM function is used to calculate the sum of the specified column. Finally, the HAVING clause is used to filter the results based on the sum of the column.

Example Query

Using the sample data from above, let's see how we can use WHERE SUM > 0 in MySQL to retrieve data for products that have sold at least one unit.

SELECT product, SUM(price * quantity) as total_sales
FROM sales
WHERE quantity > 0
GROUP BY product
HAVING total_sales > 0;

In this query, we retrieve data for the product column and the total sales (price * quantity) for each product. We use the WHERE clause to filter out any products that have not sold any units. We then group the results by the product column and finally use the HAVING clause to filter out any products that have not generated any revenue.

Conclusion

In conclusion, the WHERE SUM > 0 syntax in MySQL can be useful for retrieving data based on the sum of a column. By using the HAVING clause and the SUM function, we can filter results based on specific conditions. This can be useful in a variety of scenarios, such as identifying top-performing products, customers, or salespeople.