Vol. I · A Postgres HandbookTwelve chapters · · 756 queries

The Query & the Schema

A reading-room reference for writing PostgreSQL by hand — selects to window functions, with the schema in plain view.

EasyBasic SELECT

Find maximum, minimum, and average salary

SQL

SELECT
  MAX(salary) AS max_salary,
  MIN(salary) AS min_salary,
  ROUND(AVG(salary), 2) AS avg_salary
FROM employees;

Tested against PostgreSQL 16

Note

“Aggregate functions: MAX, MIN, AVG, SUM, COUNT work on numeric columns.