SQL Query Strategies: Handling NULL Values in Referee Filtering
Problem Context
The objective is to retrieve a list of customer names from a database table, specifically exclduing those who were referred by the customer with ID 2. A naive approach might involve a direct comparison operator in the WHERE clause.
SELECT name
FROM customer
WHERE referee_id <> 2;
However, executing this query often yiel ...
Posted on Sun, 07 Jun 2026 17:20:07 +0000 by ollmorris