STDDEV

1
SELECT 
2
  AVG(salary) AS avg_salary,
3
  STDDEV(salary) AS stddev_salary
4
FROM employees;

1
SELECT 
2
  STDDEV_SAMP(score) AS sample_stddev,
3
  STDDEV_POP(score) AS population_stddev
4
FROM test_scores;

1
SELECT 
2
  category,
3
  AVG(price) AS avg_price,
4
  STDDEV(price) AS price_variability
5
FROM products
6
GROUP BY category
7
ORDER BY price_variability DESC;