MYSQL 如何从两列（如键/值对）产生分组

Question

我必须在同一列中返回与其父级（field_name）相关的所有值。 目前我有以下查询：

SELECT dicval.id, dic.field_name, dic.description AS field_description, 
dicval.value,dicval.description FROM adenvie_data_cloud.dictionary_values dicval
INNER JOIN dictionary dic ON dicval.field_name_id = dic.id
ORDER BY dicval.id;

并返回如下：

 {
            "id": "1",
            "field_name": "address_type",
            "field_description": "Address Type Indicator",
            "value": "F",
            "description": "Company"
        },
        {
            "id": "2",
            "field_name": "address_type",
            "field_description": "Address Type Indicator",
            "value": "G",
            "description": "General Delivery"
        },
        {
            "id": "3",
            "field_name": "address_type",
            "field_description": "Address Type Indicator",
            "value": "H",
            "description": "Highway"
        },
        {
            "id": "4",
            "field_name": "address_type",
            "field_description": "Address Type Indicator",
            "value": "P",
            "description": "PO Box"
        },
        ...

是否可以在 SQL 语句中按 field_name 对结果进行分组，以便返回如下内容？

{
                "id": "3",
                "name": "addressType",
                "description": "Address Type Indicator",
                "values": {
                    "F": "Company",
                    "G": "General Delivery" ,
                    "H": "Highway",
                    "P": "PO Box",                                    
                    "R": "Rural Route ",
                    "S": "Street"  
                }

PD：

我在 SQL 语句的结尾尝试了GROUP BY dicval.id, dic.field_name没有成功。

Answer 1

最终解决方案

为了获得分组值作为键/值对的最准确查询如下：

SELECT d.*,
(SELECT CAST(
    CONCAT('[',
        GROUP_CONCAT(
            JSON_OBJECT(
                dv2.value ,dv2.description 
            )
        ),
    ']')
  AS JSON) FROM (SELECT * FROM dictionary_values dv WHERE dv.field_name_id = d.id) AS dv2) 
  AS d_value
FROM dictionary d; 
END

最后显示分组数据：

{
            "id": "1",
            "field_name": "address_type",
            "description": "Address Type Indicator",
            "category": "base",
            "d_value": "[{\"F\": \"Company\"}, {\"G\": \"General Delivery\"}, {\"H\": \"Highway\"}, {\"P\": \"PO Box\"}, {\"R\": \"Rural Route\"}, {\"S\": \"Street\"}]"
        }

仅保留使用 str_replace 解析 d_value 字符串删除 \ 并使用 str_split (PHP) 转换为数组