Agile Web Development with Rails 5, 1st Edition

Managing Tables

So far we’ve been using migrations to manipulate the columns in existing tables. Now let’s look at creating and dropping tables:

class CreateOrderHistories < ActiveRecord::Migration
  def change
    create_table :order_histories do |t|
      t.integer :order_id, null: false
      t.text :notes

      t.timestamps
    end
  end
end

create_table takes the name of a table (remember, table names are plural) and a block. (It also takes some optional parameters that we’ll look at in a minute.) The block is passed a table definition object, which we use to define the columns in the table.

Generally the call to drop_table is not needed, as create_table is reversible. drop_table accepts a single parameter, which is the name ...