Friday, January 17, 2025

When I update a view in SQL, does my original table get affected?

 No, updating a view in SQL does not directly affect the underlying table. A view is essentially a saved query that provides a virtual table of results from one or more underlying tables. When you update a view, you're modifying the data in the virtual table that the view represents.

However, the changes you make through an update to the view will typically affect the underlying table(s) from which the view is derived. The key point here is that views can be either updatable or non-updatable:

  • Updatable views: If the view is based on a single table and doesn’t have complex operations like JOINs, GROUP BY, or aggregations, you can update the underlying table through the view. In this case, the update affects the original table.

  • Non-updatable views: If the view is based on complex queries or multiple tables, it may not allow direct updates. In this case, any attempt to update the view will result in an error, or the database will prevent the update from happening.

So, to summarize:

  • Updating the view can update the underlying table if the view is updatable.
  • The table itself is affected only if the update on the view is allowed and valid.

If you're performing updates on a non-updatable view, you would need to update the underlying table(s) directly.

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