SELECT multiple columns when using GROUP_CONCAT with UNION

Question

I have a frustrating situation caused by poor database design - unfortunately that part is out of my control.

This is the table definition:

CREATE TABLE `account` (
  `account_no` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `company_name` varchar(120) NOT NULL DEFAULT '',
  `admin_name` varchar(120) NOT NULL DEFAULT '',
  `admin_email` varchar(120) DEFAULT '',
  `admin_phone_src` varchar(33) DEFAULT NULL,
  `admin_mobile_src` varchar(33) DEFAULT NULL,
  `billing_name` varchar(120) NOT NULL DEFAULT '',
  `billing_email` varchar(120) DEFAULT '',
  `billing_phone_src` varchar(33) DEFAULT NULL,
  `billing_mobile_src` varchar(33) DEFAULT NULL,
  `technical_name` varchar(120) NOT NULL DEFAULT '',
  `technical_email` varchar(120) DEFAULT '',
  `technical_phone_src` varchar(33) DEFAULT NULL,
  `technical_mobile_src` varchar(33) DEFAULT NULL
  PRIMARY KEY (`account_no`)
) ENGINE=InnoDB AUTO_INCREMENT=10476 DEFAULT CHARSET=utf8

I need to produce a list of people with the role comma delimited. I.e. admin, billing, technical may all refer to the same person (duplicated data - urgh!), or they might be 3 different people.

Given the dataset:

+------------+--------------+------------+-----------------+-----------------+------------------+--------------+-------------------+-------------------+--------------------+----------------+-----------------+---------------------+----------------------+
| account_no | company_name | admin_name | admin_email     | admin_phone_src | admin_mobile_src | billing_name | billing_email     | billing_phone_src | billing_mobile_src | technical_name | technical_email | technical_phone_src | technical_mobile_src |
+------------+--------------+------------+-----------------+-----------------+------------------+--------------+-------------------+-------------------+--------------------+----------------+-----------------+---------------------+----------------------+
|      1     | Company 1    | John       | john@email.com  | 0123456789      |                  | Dave         | dave@email.com    | 0123455789        |                    | John           | john@email.com  | 0123456789          |                      |
|      2     | Company 2    | Sarah      | sarah@email.com | 0123466789      | 0723456781       | Sarah        | sarah@email.com   | 0123466789        | 0723456781         | Sarah          | sarah@email.com | 0123466789          | 0723456781           |
|      3     | Company 3    | James      | james@email.com | 0123477789      | 0743456788       | Richard      | richard@email.com | 0123444789        | 0723444781         | Tom            | tom@email.com   | 0123433789          | 0723458881           |
+------------+--------------+------------+-----------------+-----------------+------------------+--------------+-------------------+-------------------+--------------------+----------------+-----------------+---------------------+----------------------+

I'm trying to get to:

+------------+--------------+---------+-------------------+------------+------------+-------------------------+
| account_no | company_name | name    | email             | phone_src  | mobile_src | role                    |
+------------+--------------+---------+-------------------+------------+------------+-------------------------+
|      1     | Company 1    | John    | john@email.com    | 0123456789 |            | Admin,Technical         |
|      1     | Company 1    | Dave    | dave@email.com    | 0123455789 |            | Billing                 |
|      2     | Company 2    | Sarah   | sarah@email.com   | 0123466789 | 0723456781 | Admin,Billing,Technical |
|      3     | Company 3    | James   | james@email.com   | 0123477789 | 0743456788 | Admin                   |
|      3     | Company 3    | Richard | richard@email.com | 0123444789 | 0723444781 | Billing                 |
|      3     | Company 3    | Tom     | tom@email.com     | 0123433789 | 0723458881 | Technical               |
+------------+--------------+---------+-------------------+------------+------------+-------------------------+

I've managed to use UNION to get the people into rows instead of columns (i.e. impersonating a 'sane' database design), and adding the role like this:

SELECT account_no, company_name, admin_name AS 'Name', admin_email AS 'Email', admin_phone_src AS 'Phone', admin_mobile_src AS 'Mobile', 'Admin' AS role FROM account
UNION
SELECT account_no, company_name, billing_name AS 'Name', billing_email AS 'Email', billing_phone_src AS 'Phone', billing_mobile_src AS 'Mobile', 'Billing' AS role FROM account
UNION
SELECT account_no, company_name, technical_name AS 'Name', technical_email AS 'Email', technical_phone_src AS 'Phone', technical_mobile_src AS 'Mobile', 'Technical' AS role FROM account

I am now trying to merge those rows to get DISTINCT people and produce a comma separated list of roles. I think that's possible using GROUP_CONCAT but my attempt to do that resulted in just 1 row:

SELECT t.account_no, t.company_name, t.Name, t.Email, t.Phone, t.Mobile, GROUP_CONCAT(t.role) FROM (
    SELECT account_no, company_name, admin_name AS 'Name', admin_email AS 'Email', admin_phone_src AS 'Phone', admin_mobile_src AS 'Mobile', 'Admin' AS role FROM account
    UNION
    SELECT account_no, company_name, billing_name AS 'Name', billing_email AS 'Email', billing_phone_src AS 'Phone', billing_mobile_src AS 'Mobile', 'Billing' AS role FROM account
    UNION
    SELECT account_no, company_name, technical_name AS 'Name', technical_email AS 'Email', technical_phone_src AS 'Phone', technical_mobile_src AS 'Mobile', 'Technical' AS role FROM account
) t

Any help much appreciated.

Answer 1

You need a group by to use the group_concat, GROUP BY t.account_no, t.company_name, t.Name, t.Email, t.Phone, t.Mobile

Anyway, I would do it in two separate tables, you have to much duplicate information on that way

CREATE TABLE `account` (
  `account_no` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `company_name` varchar(120) NOT NULL DEFAULT '',
  `admin_id` int(10) unsigned NOT NULL DEFAULT '',
  `billing_id` int(10) unsigned NOT NULL DEFAULT '',
  `technical_id` int(10) unsigned NOT NULL DEFAULT ''
  PRIMARY KEY (`account_no`)
) ENGINE=InnoDB AUTO_INCREMENT=10476 DEFAULT CHARSET=utf8

CREATE TABLE `people` (
  `people_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `name` varchar(120) NOT NULL DEFAULT '',
  `email` varchar(120) DEFAULT '',
  `phone_src` varchar(33) DEFAULT NULL,
  `mobile_src` varchar(33) DEFAULT NULL
  PRIMARY KEY (`people_id`)
) ENGINE=InnoDB AUTO_INCREMENT=10476 DEFAULT CHARSET=utf8