A developer encountered a puzzling issue where order queries were missing data. After extensive debugging, the root cause was traced to a misplaced WHERE clause that inadvertently filtered out valid records. The article walks through the query logic, explains how the error occurred, and provides corrected SQL examples. This case highlights the importance of careful SQL clause ordering and testing edge cases. For backend developers and database engineers, it serves as a practical reminder of how subtle syntax errors can lead to significant data integrity problems. The lesson is broadly applicable across SQL databases and query patterns.
A real-world debugging story about a SQL WHERE clause mistake that caused data loss in order queries, with step-by-step analysis.