Mysql 然后在选择的情况下使用条件视图来构建视图

我正在尝试构建一个链接多个表的视图

它是一个事件时间表列表。这个项目的一个特点是有一个带有ID和NAME列的Companys表

如果mainSubcategory是217，那么我只想使用companys.name。这很有效

如果Main子类别为216，我需要：

从company\u event\u关联的\u companys中获取company\u id，其中company\u id=companys.main子类别

使用该公司id以companys.name填充该记录的bands列，其中companys.id=company\u event\u associated\u companys.company\u id

SQL代码：

CREATE OR REPLACE VIEW v_events_7 AS
    SELECT company_events.id, 
           companies.city, 
           company_events.start_date, 
           company_events.start_time,
           company_event_associated_companies.company_id,
           CASE
               WHEN companies.mainSubcategory = '217'
                   THEN companies.name 
               WHEN companies.mainSubcategory = '216'
                   THEN companies.name /*This is where I need the name as described above*/
           END Band
    FROM `company_events`

更新-下面的代码与Panjak在回答中提供的代码略有不同。我得把那辆车挪动一下

(CASE
WHEN 
  companies.mainSubcategory = '217'
THEN
  companies.name 
WHEN
  companies.mainSubcategory = '216') AND
  companies.id = company_event_associated_companies.company_id)

THEN
(SELECT companies.name  FROM companies WHERE 
         companies.id = '332')
END ) AS 'Band'

注意-我将companys.id硬连线到332，但我确信当我使用实际的company id提取字段时，它会工作

请尝试此查询：

---

非常感谢。我做了一个小的修改，作为更新添加到原始问题中。你让我走对了方向！

CREATE OR REPLACE VIEW v_events_7 AS
SELECT company_events.id, 
       companies.city, 
       company_events.start_date, 
       company_events.start_time,
       company_event_associated_companies.company_id,
       (CASE WHEN companies.mainSubcategory = '217'
           THEN companies.name 
           WHEN companies.mainSubcategory = '216'
           THEN companies.name
           ELSE (SELECT columnName FROM tableName WHERE 
         companies.mainSubcategory = 'YourData'
 /*This is where I need the name as described above*/ 
   END END) Band
   FROM `company_events`