title: PG:Error relation does not exist
body: <p>I am using Rails 3.2.x and also using RailsAdmin.</p>
  
  <p>I have run many migrations and changed my DB structure many times. As a result of that, I am getting a PG:Error saying that a relation doesn't exist for a table that really doesn't exist.</p>
  
  <p>This is the error:</p>
  
  <pre><code>ActiveRecord::StatementInvalid at /
  PG::Error: ERROR:  relation "addresses" does not exist
  LINE 5:              WHERE a.attrelid = '"addresses"'::regclass
                                          ^
  :             SELECT a.attname, format_type(a.atttypid, a.atttypmod),
                       pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod
  </code></pre>
  
  <p>So in short, when I go to <code>/admin</code> the error shown in my development.log is this:</p>
  
  <pre><code>Started GET "/admin" for 127.0.0.1 at 2013-07-04 02:24:07 -0500
  Processing by RailsAdmin::MainController#dashboard as HTML
    Cart Load (0.5ms)  SELECT "carts".* FROM "carts" WHERE "carts"."id" = $1 LIMIT 1  [["id", 5]]
    User Load (0.4ms)  SELECT "users".* FROM "users" WHERE "users"."id" = 1 LIMIT 1
     (0.6ms)  SELECT COUNT(*) FROM "roles" INNER JOIN "users_roles" ON "roles"."id" = "users_roles"."role_id" WHERE "users_roles"."user_id" = 1 AND (((roles.name = 'admin') AND (roles.resource_type IS NULL) AND (roles.resource_id IS NULL)))
     (0.6ms)  SELECT COUNT(*) FROM "roles" INNER JOIN "users_roles" ON "roles"."id" = "users_roles"."role_id" WHERE "users_roles"."user_id" = 1 AND (((roles.name = 'seller') AND (roles.resource_type IS NULL) AND (roles.resource_id IS NULL)))
  PG::Error: ERROR:  relation "addresses" does not exist
  LINE 5:              WHERE a.attrelid = '"addresses"'::regclass
                                          ^
  :             SELECT a.attname, format_type(a.atttypid, a.atttypmod),
                       pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod
                FROM pg_attribute a LEFT JOIN pg_attrdef d
                  ON a.attrelid = d.adrelid AND a.attnum = d.adnum
               WHERE a.attrelid = '"addresses"'::regclass
                 AND a.attnum &gt; 0 AND NOT a.attisdropped
               ORDER BY a.attnum
  
  Completed 500 Internal Server Error in 1269ms
  
  ActiveRecord::StatementInvalid - PG::Error: ERROR:  relation "addresses" does not exist
  LINE 5:              WHERE a.attrelid = '"addresses"'::regclass
                                          ^
  :             SELECT a.attname, format_type(a.atttypid, a.atttypmod),
                       pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod
                FROM pg_attribute a LEFT JOIN pg_attrdef d
                  ON a.attrelid = d.adrelid AND a.attnum = d.adnum
               WHERE a.attrelid = '"addresses"'::regclass
                 AND a.attnum &gt; 0 AND NOT a.attisdropped
               ORDER BY a.attnum
  </code></pre>
  
  <p>How do I fix this?</p>