title: Postgresql error on inserting new row 'PG::NotNullViolation: ERROR: null value in column "id" violates not-null constraint'
body: <p>I am just migrate my us server to an eu region on <code>heroku</code>, and <code>restore</code> the old <code>database backup</code> to new server. Unfortunately I am getting following <code>error</code> while try to <code>insert an new row</code> to one of table </p>
  
  <pre><code>INSERT INTO "users" ("created_at", "id", ...) VALUES ($1, $2, ...) [["created_at", Thu, 13 Oct 2016 23:53:17 CEST +02:00], ["id", nil], ...]
  
  ActiveRecord::StatementInvalid: PG::NotNullViolation: ERROR: null value in column "id" violates not-null constraint
  
  DETAIL: Failing row contains (null, ...)
  </code></pre>
  
  <p>My schema looks like following </p>
  
  <pre><code>create_table "users", :id =&gt; false, :force =&gt; true do |t|
     t.integer  "id",          :null =&gt; false  
     t.datetime "created_at",  :null =&gt; false
     ...
  end
  </code></pre>
  
  <p>How can I solve this issue? </p>