eolas/zk/Aggregate_functions_in_SQL.md

categories	tags
Databases Programming Languages	SQL

Aggregate functions in SQL

Aggregate functions enable us to return data about the data that a table holds. For example the sum of a given column or its average.

Count return with custom variable

SELECT COUNT(*) AS total_sales
FROM SALES

Sum

SELECT SUM(price) as total_value
FROM sales

Average

SELECT AVG(price) as average_income
FROM sales

Applying aggregate function with sorting applied

SELECT COUNT(*) AS total_sales
FROM sales
GROUP BY employee_id