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我有一个高度非结构化的 JSON 字符串，作为调用 REST API 的响应：

{
    "info": "Test Json Structure",
    "Owner": "Self-Owned",
    "managedObjects": [{
            "Name": "Device1",
            "Class": "A"
        }, {
            "Name": "Device2",
            "Class_145": "Ax01",
            "Class_11": "B",
            "Type_125478": {
                "Model": "1",
                "Manufacturer": "External"
            },
            "Type_SD": {
                "Model": "00",
                "Manufacturer": "Internal"
                }
        }, {
            "Name": "Device3",
            "Class_x": "Cx11",
            "Class_T": "C8Y",
            "Type": {
                "Model": "1x",
                "Manufacturer": "Internal"
            }
        }
    ]
}

如何使用 T-SQL 动态解析此对象，以便所有子元素表示表的列？更重要的是，如何处理Type, Type_125478,Type_SD对象，实际上它们具有相同的结构 ( Model, Manufacturer)，但它们的名称有些不同。还要记住，设备可能会发送一个新的标识符 ( Type_XYZ)，它以前不存在，但幸运的是具有相同的结构 ( Model, Manufacturer)。

4

1 回答 1

2

您可能会使用类似这样的方法将全部内容分解为表格结构并继续执行此操作（需要 SQL-Server 版本 v2016+）：

DECLARE @YourJSON NVARCHAR(MAX)=
N'{
    "info": "Test Json Structure",
    "Owner": "Self-Owned",
    "managedObjects": [{
            "Name": "Device1",
            "Class": "A"
        }, {
            "Name": "Device2",
            "Class_145": "Ax01",
            "Class_11": "B",
            "Type_125478": {
                "Model": "1",
                "Manufacturer": "External"
            },
            "Type_SD": {
                "Model": "00",
                "Manufacturer": "Internal"
                }
        }, {
            "Name": "Device3",
            "Class_x": "Cx11",
            "Class_T": "C8Y",
            "Type": {
                "Model": "1x",
                "Manufacturer": "Internal"
            }
        }
    ]
}';

--查询

SELECT A.info
      ,A.[Owner]
      ,C.[key] AS TagName
      ,CASE WHEN D.Model IS NULL THEN C.[value] END AS TagValue 
      ,D.Model
      ,D.Manufacturer
FROM OPENJSON(@YourJSON)
WITH(info NVARCHAR(MAX)
    ,[Owner] NVARCHAR(MAX)
    ,managedObjects NVARCHAR(MAX) AS JSON) A
OUTER APPLY OPENJSON(A.managedObjects) B
OUTER APPLY OPENJSON(B.[value]) C
OUTER APPLY OPENJSON(CASE WHEN ISJSON(C.[value])=1 THEN C.[value] END) 
WITH (Model NVARCHAR(MAX)
     ,Manufacturer NVARCHAR(MAX))D;

- 结果

+---------------------+------------+-------------+----------+-------+--------------+
| info                | Owner      | TagName     | TagValue | Model | Manufacturer |
+---------------------+------------+-------------+----------+-------+--------------+
| Test Json Structure | Self-Owned | Name        | Device1  |       |              |
+---------------------+------------+-------------+----------+-------+--------------+
| Test Json Structure | Self-Owned | Class       | A        |       |              |
+---------------------+------------+-------------+----------+-------+--------------+
| Test Json Structure | Self-Owned | Name        | Device2  |       |              |
+---------------------+------------+-------------+----------+-------+--------------+
| Test Json Structure | Self-Owned | Class_145   | Ax01     |       |              |
+---------------------+------------+-------------+----------+-------+--------------+
| Test Json Structure | Self-Owned | Class_11    | B        |       |              |
+---------------------+------------+-------------+----------+-------+--------------+
| Test Json Structure | Self-Owned | Type_125478 |          | 1     | External     |
+---------------------+------------+-------------+----------+-------+--------------+
| Test Json Structure | Self-Owned | Type_SD     |          | 00    | Internal     |
+---------------------+------------+-------------+----------+-------+--------------+
| Test Json Structure | Self-Owned | Name        | Device3  |       |              |
+---------------------+------------+-------------+----------+-------+--------------+
| Test Json Structure | Self-Owned | Class_x     | Cx11     |       |              |
+---------------------+------------+-------------+----------+-------+--------------+
| Test Json Structure | Self-Owned | Class_T     | C8Y      |       |              |
+---------------------+------------+-------------+----------+-------+--------------+
| Test Json Structure | Self-Owned | Type        |          | 1x    | Internal     |
+---------------------+------------+-------------+----------+-------+--------------+

提示：您可以将B.[key]结果添加为对象标识符。

简而言之，这个想法

  • 我们使用第一个OPENJSON进入您的 JSON。-clauseWITH允许将 JSON-props 寻址为列。我们managedObejcts自己返回为 JSON。
  • 我们再使用一个OPENJSON来深入管理对象。
  • 这将返回一个对象数组。我们可以将value传入另一个OPENJSON。
  • 每当value可以单独解释为 JSON 时，我们会使用更多OPENJSON，这次WITH再次使用 - 子句来获取内部道具作为列。

您可以将此结果插入到表中（声明的、临时的、物理的......）并继续使用这个易于阅读的集合。

于 2020-10-21T16:32:50.217 回答