title: Why isn't my schema.rb file updated?
body: <p>I recently looked at my schema.rb file and was alarmed to find that certain columns that do exist in my database do not appear, and some tables are missing entirely. The missing columns were added to the database through "def change add_column" migrations, though some columns that were added in that way do appear as expected in schema.rb.</p>
  
  <p>On closer inspection, I realized that schema.rb has not been updated since I created the Users table.</p>
  
  <p>20151019205241_create_users.rb:</p>
  
  <pre><code>class CreateUsers &lt; ActiveRecord::Migration
    def change
      create_table :users do |t|
        t.string :name
        t.string :email
        t.timestamps null: false
      end
    end
  end
  </code></pre>
  
  <p>This has not caused an issue for me in practice, but I thought schema.rb was supposed to be kept automatically updated, and that it would be important to have it updated in order to recreate the database. Can anyone help me figure out why it would not be updating?</p>
  
  <p>One possibility is that it stopped being updated when I switched my database from sqlite3 to postgresql. I don't remember exactly, but I think the timing makes sense.</p>