如何使用 SQL Server 解析嵌套 JSON 数组

我目前能够使用 SQL Server 解析 JSON 文件的大部分内容OPENJSON WITH (...句法。但是，这个特定文件包含我不知道如何处理的嵌套数组。

我读到的许多示例都将 JSON 引用为变量。在这种情况下，我调用一个文件：

select DEV_JSON.*
from OPENROWSET
(BULK 'C:\Users\Myuser\Documents\JSON_extract.json', SINGLE_CLOB) as my_datafile
 CROSS APPLY OPENJSON(BulkColumn) 
WITH
  (DOC_ID           varchar(100)  '$.doc._id',
   DOC_REV          varchar(45)   '$.doc._rev',
   DELY_APPL_NAME   varchar(20)   '$.doc.delivery.application',
   DELY_SENT_BY     varchar(25)   '$.doc.delivery.sender.id',
   DELY_SENT_TYPO   varchar(20)   '$.doc.delivery.sender.type',
   .....
   ....
   ...
   ..) as DEV_JSON

其中一个属性包含一个嵌套数组。下面我复制了 JSON 的前 5 个属性，以及嵌套的“recipients”数组。

如何构建 SQL 来解析此部分？

"doc": {
    "_id": "[email protected] /cdn-cgi/l/email-protection",
    "_rev": "3-e119db13dae8d50ae0c4579ba9c87fc9",
    "delivery": {
        "application": "App_XYZ",
        "sender": {
            "id": "[email protected] /cdn-cgi/l/email-protection",
            "type": "user"
        },
        "recipients": [{
                "type": "email",
                "recipient": "\"Artzer, Daniel J\" <[email protected] /cdn-cgi/l/email-protection>",
                "sentTS": "2017-10-18T13:04:00.133Z"
            },
            {
                "type": "email",
                "recipient": "\"Higgins, Laura L\" <[email protected] /cdn-cgi/l/email-protection>",
                "sentTS": "2017-10-18T13:04:00.133Z"
            },
            {
                "type": "email",
                "recipient": "\"Friedman, Brian\" <[email protected] /cdn-cgi/l/email-protection>",
                "sentTS": "2017-10-18T13:04:00.133Z"
            },
            {
                "type": "email",
                "recipient": "\"Garcia, Charlie M\" <[email protected] /cdn-cgi/l/email-protection>",
                "sentTS": "2017-10-18T13:04:00.133Z"
            }
        ]
    },

我刚刚遇到了同样的问题，最后我用多个 CROSS APPLY 子句解决了它。

这是我的 JSON 的示例：

DECLARE @PermsJSON NVARCHAR(MAX) =
N'[{
    "AppId": 1,
    "Perms":
    [{

        "Permission": ["AA", "BB"],
        "PermissionTypeID": 2
    },
    {
        "Permission": ["10"],
        "PermissionTypeID": 1
    }]
},
{
    "AppId": 2,
    "Perms":
    [{

        "Permission": ["IM", "NM"],
        "PermissionTypeID": 2
    },
    {
        "Permission": ["42"],
        "PermissionTypeID": 1
    }]
}]';

然后我可以使用以下查询解析它：

SELECT
    a.AppId
    ,[Permission] = c.Value
    ,b.PermissionTypeID
FROM
    OPENJSON(@PermsJSON)
    WITH
        (
            AppId INT N'$.AppId'
            ,Perms NVARCHAR(MAX) AS JSON
        ) AS a
CROSS APPLY
    OPENJSON(a.Perms)
    WITH
        (
            PermissionTypeID INT
            ,[Permission] NVARCHAR(MAX) AS JSON
        ) AS b
CROSS APPLY OPENJSON(b.Permission) AS c;

结果如下所示：

AppId   Permission  PermissionTypeID
1       AA          2
1       BB          2
1       10          1
2       IM          2
2       NM          2
2       42          1