Deleting all records in a database table

If you are looking for a way to it without SQL you should be able to use delete_all.

Post.delete_all

or with a criteria

Post.delete_all "person_id = 5 AND (category = 'Something' OR category = 'Else')"

See here for more information.

The records are deleted without loading them first which makes it very fast but will break functionality like counter cache that depends on rails code to be executed upon deletion.

To delete via SQL

Item.delete_all # accepts optional conditions

To delete by calling each model's destroy method (expensive but ensures callbacks are called)

Item.destroy_all # accepts optional conditions

All here

if you want to completely empty the database and not just delete a model or models attached to it you can do:

rake db:purge

you can also do it on the test database

rake db:test:purge