Sqlserver Error: Ambiguous Column

How to fix the "ambiguous column" error in Sqlserver.

The Error

column reference "column_name" is ambiguous

Solution

1. Always qualify column names with table aliases when using JOINs.
2. Use meaningful aliases (e.g., 'e' for employees, 'd' for departments).
3. Be explicit even when column names seem unique - it improves readability.

Example Fix

SELECT e.id, e.name
FROM employees e
JOIN departments d ON e.department_id = d.id;
-- Correct: table alias qualifies columns