How can I truncate the tax class tables and not break my install?

Question

I'm having trouble editing and adding the Tax Classes in our current installation.

When I looked the classes up in the database I saw that a new entry gets a primary key of '0' and this is causing issues. I'm not sure what the issue is aside from not updating with the correct values after an edit or displaying 'An error occurred while saving this tax class.' when trying to add a new Tax Class as the logs aren't showing anything. But from previous experience I'm almost certain its because of an Integrity constraint violation.

Previously when migrating our database I fixed the Integrity constraint violation issue for other tables by truncating them but I know that these tax tables have foreign key relations with some of the product tables so I want to proceed carefully.

How can I safely truncate these tables? I am working on a development environment so I have room to experiment. Also all the current products only use 1 tax class so I can re-add it later.

Answer 1

You need to truncate tax_calculation_rate this table and try again hope it will work. Before doing any truncate please keep backup of your db.