Question

Basically I am creating a summary table.

The issue is that sometimes the data in the primary table is modified manually. I am using an ON DUPLICATE KEY UPDATE, however I also need something like ON MISSING KEY DELETE. The summary needs to update to the changed data.

Is the best solution really to simply delete all summary records and re-run the INSERT SELECT query? It just doesn’t seem like a good idea.

Any keys not in the select query, should not be in the summary table.

Answer 1

After you’ve populated the summary_table, you could do this:

DELETE s FROM summary_table s LEFT OUTER JOIN original_table o ON s.id = o.id
WHERE o.id IS NULL;

That will remove from summary_table any rows where the id no longer exists in the original_table.

I don’t think there’s any way you can do this in one statement.