Question

我在WordPress网站上有一个表格，使用ARForms插件捕获姓名，电子邮件和电话号码，但是采用愚蠢的数据库布局。

我有一个像这样的MYSQL WordPress表：

|id          |entry_value        |field_id        |entry_ID      |
|1           |John               |74              |1             |
|2           |Smith              |75              |1             |
|3           |555 1234           |76              |1             |
|4           |jsmith@mail.com    |77              |1             |
|5           |Sue                |74              |2             |
|6           |Brown              |75              |2             |
|7           |555 4321           |76              |2             |
|8           |sbrown@mail.com    |77              |2             |

我正在使用其他插件导出报告来尝试查询此表，并为填写表单的所有用户获取报告。

我希望它采用以下格式：

|ID           |Name              |Surname          |Email            |Telephone
|1            |John              |Smith            |jsmith@mail.com  |555 1234
|2            |Sue               |Brown            |sbrown@mail.com  |555 4321

我已经尝试了以下几个示例，但我一直收到NULL返回。我需要以某种方式过滤掉它，并且只在有价值的地方进行调整。注意：与上面的示例相比，还有2个额外字段，InterestedIn和省：

create view users_subscribed as (
  select 
    a.entry_id,
    a.field_id,
    case when field_id = '74' then entry_value end as FirstName,
    case when field_id = '75' then entry_value end as LastName,
    case when  field_id = '76' then entry_value end as Email,
    case when  field_id = '78' then entry_value end as Phone,
    case when  field_id = '79' then entry_value end as InterestedIn,
    case when  field_id = '81' then entry_value end as Province
  from ch_arf_entry_values a
);

create view users_subscribed_extended_pivot as (
  select
    entry_id as ID,
    FirstName,
    LastName,
    Email, 
    Phone,
    InterestedIn,
    Province
  from users_subscribed
  group by entry_id
);


SELECT * FROM users_subscribed_extended_pivot ;

任何人都可以协助......

Answer 1

你缺少，GROUP BY和MAX聚合函数

您不需要两个视图，您可以在一个视图中执行此操作

  select 
    a.entry_id,
    MAX(case when field_id = 74 then entry_value end) as FirstName,
    MAX(case when field_id = 75 then entry_value end) as LastName,
    MAX(case when  field_id = 76 then entry_value end) as Email,
    MAX(case when  field_id = 78 then entry_value end) as Phone,
    MAX(case when  field_id = 79 then entry_value end) as InterestedIn,
    MAX(case when  field_id = 81 then entry_value end) as Province
  from ch_arf_entry_values a
  GROUP BY a.entry_id

MySQL Pivot一个表，其中列是自己的行

1 个答案: