SQL for Database Validation

The ISS STOXX employee directory requires a basic data-quality check for short display names. Write a PostgreSQL query that returns employee records where employee_name contains exactly four letters.

Requirements

1. Return the employee ID and employee name for matching records.
2. Include only names consisting of exactly four alphabetic characters. Exclude shorter, longer, numeric, punctuation-containing, and NULL values.
3. Sort the results alphabetically by employee name, then by employee ID.