How can I Delete Duplicate Rows in SQL while keeping the First Occurrence?

To delete duplicate rows in SQL while keeping the first occurrence:

1. Identify the columns that define duplicates (e.g., columns like column1, column2).
2. Use a window function like ROW_NUMBER() to assign a unique number to each row within the duplicate groups.
3. Keep only the row with the smallest identifier (e.g., the first row) and delete the other duplicate rows.

Alternatively, if the database doesn’t support window functions, use a subquery or a self-join to delete duplicates while keeping the first occurrence.

Always back up your data before running delete operations to prevent accidental data loss.