IntermediateGROUP BY & Aggregation

Histogram: salary distribution with width_bucket

The query

SQL

SELECT
  WIDTH_BUCKET(salary, 20000, 150000, 13) AS bucket,
  (20000 + (WIDTH_BUCKET(salary, 20000, 150000, 13) - 1) * 10000)::TEXT || 'k-'
  || (20000 + WIDTH_BUCKET(salary, 20000, 150000, 13) * 10000)::TEXT || 'k' AS range,
  COUNT(*) AS employees,
  REPEAT('█', COUNT(*)) AS bar
FROM employees
WHERE salary IS NOT NULL
GROUP BY bucket
ORDER BY bucket;

Tested against PostgreSQL 16

Note

“WIDTH_BUCKET distributes values into equal-width buckets. REPEAT draws ASCII bar chart. Classic histogram query.

Tables referenced

employees10 cols