Note: Remember dropping a table will remove all the data from it.

I recently had to remove a table from a Rails application, so, I want to share ways to do it.

Using a Migration

why this option?

• It’s a standard way to make changes to the database.
• It’s reversible, so I can rollback the change if needed. (won’t recover the data though).

rails generate migration DropUsers

class DropUsers < ActiveRecord::Migration[7.0]
  def change
    drop_table :users do |t|
      t.string :name
      t.string :email
      t.timestamps
    end
  end
end

I saw some blog posts that only use drop_table :users, but that is not reversible, you may see this error when rolling back:

To avoid mistakes, drop_table is only reversible if given options or a block (can be empty).

doctors/db/migrate/20240228054356_drop_users.rb:3:in `change'

Caused by:
ActiveRecord::IrreversibleMigration:

To avoid mistakes, drop_table is only reversible if given options or a block (can be empty).

use the block to avoid the error.

Using the Rails Console

why this option?

• I don’t want to track the history of the change.

bin/rails console
ActiveRecord::Base.connection.execute("DROP TABLE IF EXISTS users;")

# or using the helper method:

ActiveRecord::Migration.drop_table :users

Using a Database Client

why this option?

• I don’t care about the history of the change.
• I don’t have access to run Rails commands.

Depending on the database you are using, you can use the client to drop the table.

For example, using the psql client for PostgreSQL:

psql -U username -d database_name
DROP TABLE IF EXISTS users;

Here you can see the pull request where I dropped the table.