使用LEFT OUTER JOIN返回一个匹配的行和其他仅匹配的ID

Question

我有一个大型数据库，在22个表中大约有190列。 有一些表允许多个条目进入数据库，所有值都由外键引用。 当我使用LEFT OUTER JOIN如果单个列中有多个与特定ID匹配的条目，则它会像仅更改表字段之前一样，创建一个包含所有信息的新行。 例如：

+-----------+---------------------------+-----------------------------+----------------+-------+-------+---------+-------------------------------+
| CompanyID | Name                      | Address                     | City           | State | Zip   | Country | Website                       |
+-----------+---------------------------+-----------------------------+----------------+-------+-------+---------+-------------------------------+
|       227 | Hello Company             | 123 blvd                    | Boom           | OK    | 56008 | USA     | www.imtired.com               |
|       228 | Test Company              | 87 Wesley Street            | Denham         | LA    | 21726 | USA     | www.tests.com                 |
|       229 | Testing Company           | 2 US hwy 281 N.             | Antonio        | TX    | 64258 | USA     | www.modeling.com              |
|       230 | TestCompany               | 45 W. 95th St               | Oak Lawn       | IL    | 61453 | USA     | www.express.com               |
|       235 | Encore                    | 2142 S. Patterson           | City           | IA    | 43106 | USA     | www.boomsite.com              |
|       235 | Encore                    | 2142 S. Patterson           | City           | IA    | 43106 | USA     | www.testingsite.com           |
+-----------+---------------------------+-----------------------------+----------------+-------+-------+---------+-------------------------------+

您会看到Encore公司有两行，只有网站不同，有没有办法做到这一点：

+-----------+---------------------------+-----------------------------+----------------+-------+-------+---------+-------------------------------+
| CompanyID | Name                      | Address                     | City           | State | Zip   | Country | Website                       |
+-----------+---------------------------+-----------------------------+----------------+-------+-------+---------+-------------------------------+
|       227 | Hello Company             | 123 blvd                    | Boom           | OK    | 56008 | USA     | www.imtired.com               |
|       228 | Test Company              | 87 Wesley Street            | Denham         | LA    | 21726 | USA     | www.tests.com                 |
|       229 | Testing Company           | 2 US hwy 281 N.             | Antonio        | TX    | 64258 | USA     | www.modeling.com              |
|       230 | TestCompany               | 45 W. 95th St               | Oak Lawn       | IL    | 61453 | USA     | www.express.com               |
|       235 | Encore                    | 2142 S. Patterson           | City           | IA    | 43106 | USA     | www.boomsite.com              |
|           |                           |                             |                |       |       |         | www.testingsite.com           |
+-----------+---------------------------+-----------------------------+----------------+-------+-------+---------+-------------------------------+

这是我正在使用的查询的摘要：

SELECT * FROM `company` C 
LEFT OUTER JOIN owner O USING ( CompanyID ) 
LEFT OUTER JOIN sales S USING ( CompanyID )

Answer 1

您可以在mySQL中尝试类似的方法。 每当有多行内容相同的网站（网站除外）时，它将为逗号分隔的网站

SELECT *,GROUP_CONCAT(website,',') as website FROM `company` C 
LEFT OUTER JOIN owner O USING ( CompanyID ) 
LEFT OUTER JOIN sales S USING ( CompanyID )
GROUP BY CompanyID