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sql - 将多行合并为一列中具有多个行值的行

问题描述

我目前正在构建一个查询以从我的数据库中检索一些数据，我需要在一行中访问一些具有公共 id 的信息。

使用此查询：

select 
        missions_answer.response_id as "response",
        crm_player."document" as "document",
        missions_question.label as "label",
        missions_answertext.body as "bill #",
        missions_answerselectmultiple.body as "product",
        missions_answerinteger.body as "answer" 
from missions_answer 
    left join missions_question on missions_answer.question_id = missions_question.id 
    left join missions_answertext on missions_answer.id = missions_answertext.answer_ptr_id 
    left join missions_answerselectmultiple on missions_answer.id = missions_answerselectmultiple.answer_ptr_id
    left join missions_answerinteger on missions_answer.id = missions_answerinteger.answer_ptr_id 
    left join missions_response on missions_answer.response_id = missions_response.id
    left join crm_player on missions_response.player_id = crm_player.id
    LEFT JOIN crm_user ON crm_player.user_id = crm_user.id
    where  missions_answer.response_id = '71788176'
    group by missions_answer.response_id, crm_player.document,missions_answertext.body,
        missions_question.label,
        missions_answerselectmultiple.body ,
        missions_answerinteger.body,
        crm_user.first_name,
        crm_user.last_name

这是我目前拥有的：

+   response    +     document    +    label    +    bill #  +    product  +  answer
-   71788176    -     79907201    -    bill #   -    26899   -             -
-   71788176    -     79907201    -    amount   -            -             -    1
-   71788176    -     79907201    -    product  -      -    {"name": "Shoes"}   -
-   71788176    -     79907201    -    price    -            -             -  25.99

这就是我要找的：

+   response    +     document    +    bill #  +    product  +  amount  +   price 
-   71788176    -     79907201    -    26899   -     shoes   -       1  -   25.99

我一直在尝试使用crosstab，但我仍然无法找到它，提前感谢任何提示或帮助。

标签： sqlpostgresql

解决方案

从您当前的状态，您可以使用以下FILTER子句简单地进行数据透视：

演示：db<>小提琴

SELECT
    response,
    document,
    MAX(bill) FILTER (WHERE label = 'bill') as bill,
    MAX(answer) FILTER (WHERE label = 'amount') as amount,
    MAX(product) FILTER (WHERE label = 'product') as product,
    MAX(answer) FILTER (WHERE label = 'price') as price
FROM t
GROUP BY response, document

我不太确定，你原来的桌子是什么样子的。如果它更像这样：

response | document | label   | value
-------: | -------: | :------ | :----
71788176 | 79907201 | bill    | 26899
71788176 | 79907201 | amount  | 1    
71788176 | 79907201 | product | shoes
71788176 | 79907201 | price   | 25.99

然后你可以像这样修改查询：

演示：db<>小提琴

SELECT
    response,
    document,
    MAX(value) FILTER (WHERE label = 'bill') as bill,
    MAX(value) FILTER (WHERE label = 'amount') as amount,
    MAX(value) FILTER (WHERE label = 'product') as product,
    MAX(value) FILTER (WHERE label = 'price') as price
FROM t
GROUP BY response, document

编辑：将 JSON 值添加到产品列：

演示：db<>小提琴

变体 1：您可以简单地将类型json转换为 type text：

MAX(product::text) FILTER (WHERE label = 'product') as product,

变体 2：您从"name"属性中读取值：

MAX(product ->> 'name') FILTER (WHERE label = 'product') as product,

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