title: MySQL left join with group_concat
body: <p>I have a SQL Fiddle with the table creation and query that I'm having issues with: <a href="http://www.sqlfiddle.com/#!9/3404e/1" rel="nofollow">http://www.sqlfiddle.com/#!9/3404e/1</a></p>
  
  <p>Here is the table creation script:</p>
  
  <pre><code>CREATE TABLE IF NOT EXISTS `collection` (
    `id` bigint(20) unsigned NOT NULL,
    `name` varchar(50) NOT NULL,
    `label` varchar(120) NOT NULL,
    `label_plural` varchar(120) NOT NULL);
  
  INSERT INTO `collection` (`id`, `name`, `label`, `label_plural`) VALUES
      (1, 'account', 'Account', 'Accounts');
  
  CREATE TABLE IF NOT EXISTS `field` (
    `id` bigint(20) unsigned NOT NULL,
    `name` varchar(50) NOT NULL,
    `label` varchar(120) NOT NULL,
    `collection_id` bigint(20) unsigned NOT NULL);
  
  INSERT INTO `field` (`id`, `name`, `label`, `collection_id`) VALUES
      (1, 'name', 'Name', 1),
      (2, 'state', 'State', 1);
  
  CREATE TABLE IF NOT EXISTS `option` (
    `id` bigint(20) unsigned NOT NULL,
    `record_type_id` bigint(20) unsigned DEFAULT NULL,
    `field_id` bigint(20) unsigned NOT NULL,
    `value` varchar(120) NOT NULL);
  
  INSERT INTO `option` (`id`, `record_type_id`, `field_id`, `value`) VALUES
      (1, NULL, 2, 'CO'),
      (2, NULL, 2, 'NE'),
      (3, NULL, 2, 'BC'),
      (4, NULL, 2, 'MB'),
      (5, 1, 2, 'CO'),
      (6, 1, 2, 'NE'),
      (7, 2, 2, 'BC'),
      (8, 2, 2, 'MB');
  
  CREATE TABLE IF NOT EXISTS `record_type` (
    `id` bigint(20) unsigned NOT NULL,
    `name` varchar(120) NOT NULL,
    `collection_id` bigint(20) unsigned NOT NULL);
  
  INSERT INTO `record_type` (`id`, `name`, `collection_id`) VALUES
      (1, 'US', 1),
      (2, 'Canada', 1);
  </code></pre>
  
  <p>Here is the query I'm trying to run:</p>
  
  <pre><code>select
      `field`.`name`,
      `field`.`label`,
      ifnull(group_concat(`option`.`value` separator ';'), '') as `options`
  from
      `field`
  join
      `collection` on
          `collection`.`id` = `field`.`collection_id`
  join
      `record_type` on
          `record_type`.`collection_id` = `collection`.`id`
  left join
      `option` on
          `option`.`record_type_id` = `record_type`.`id` and
          `option`.`field_id` = `field`.`id`
  where
      `record_type`.`name` = 'US' and
      `collection`.`name` = 'account';
  </code></pre>
  
  <p>What I'm expecting are two rows as follows:</p>
  
  <pre><code>+-------+-------+---------+
  | name  | label | options |
  +-------+-------+---------+
  | name  | Name  | NULL    |
  | state | State | CO;NE   |
  +-------+-------+---------+
  </code></pre>
  
  <p>But I'm only receiving the state row. If I remove the group_concat line I get the three lines as follows, so I know everything is getting returned:</p>
  
  <pre><code>+-------+-------+--------+
  | name  | label | option |
  +-------+-------+--------+
  | name  | Name  | NULL   |
  | state | State | CO     |
  | state | State | NE     |
  +-------+-------+--------+
  </code></pre>