Ruby on Rails Rails Cookbook - Advanced rails recipes/learnings and coding techniques Playing with Tables using rails console
Example
View tables
ActiveRecord::Base.connection.tables
Delete any table.
ActiveRecord::Base.connection.drop_table("users")
------------OR----------------------
ActiveRecord::Migration.drop_table(:users)
------------OR---------------------
ActiveRecord::Base.connection.execute("drop table users")
Remove index from existing column
ActiveRecord::Migration.remove_index(:users, :name => 'index_users_on_country')
where country is a column name in the migration file with already added index in users table as shown below:-
t.string :country,add_index: true
Remove foreign key constraint
ActiveRecord::Base.connection.remove_foreign_key('food_items', 'menus')
where menus has_many food_items and their respective migrations too.
Add column
ActiveRecord::Migration.remove_column :table_name, :column_name
for example:-
ActiveRecord::Migration.add_column :profiles, :profile_likes, :integer, :default => 0
