php - Mysql 2跨表视图不与1 = 1关系成一个视图

Question

我有一个四列的 mysql 表subfield_id, submission_id, field_id, value

我提出了两个观点：

1.

SELECT submission_id, 
       MAX( CASE field_id WHEN '1' THEN value ELSE '0' END ) Usernumber,
       MAX( CASE field_id WHEN '2' THEN value ELSE '0' END ) Company, 
       MAX( CASE field_id WHEN '3' THEN value ELSE '0' END ) Zipp, 
FROM table
GROUP BY submission_id

结果表列：Submission_id, Usernumber, Company, Zipp

2.

SELECT submission_id, 
       MAX( CASE field_id WHEN '4' THEN value ELSE '0' END ) Usernumber1, 
       MAX( CASE field_id WHEN '5' THEN value ELSE '0' END ) Partnernumber 
FROM table 
GROUP BY submission_id

结果表列：Submission_id, Usernumber1, Partnernumber

Usernumber并且Usernumber1是相同的数字

如何使用以下列创建视图？

Usernumber, Company,  Zipp, Partnernumber

Answer 1

只需将其写在一个查询中：

SELECT submission_id, 
       MAX( CASE field_id WHEN '1' THEN value ELSE '0' END ) as Usernumber,
       MAX( CASE field_id WHEN '2' THEN value ELSE '0' END ) as Company, 
       MAX( CASE field_id WHEN '3' THEN value ELSE '0' END ) as Zipp, 
       MAX( CASE field_id WHEN '5' THEN value ELSE '0' END ) as Partnernumber 
FROM table
GROUP BY submission_id;

视图不会真正帮助您完成此查询。

编辑：

根据您的评论：

select *
from view1 v1 join
     view2 v2
     using (Usernumber);