在SQL Server中解析JSON

参考Microsoft提供的示例：

DECLARE @json NVARCHAR(MAX)
SET @json =  
N'[  
       { "id" : 2,"info": { "name": "John", "surname": "Smith" }, "age": 25 },  
       { "id" : 5,"info": { "name": "Jane", "surname": "Smith" }, "dob": "2005-11-04T12:00:00" }  
 ]'  

SELECT *  
FROM OPENJSON(@json)  
  WITH (id int 'strict $.id',  
        firstName nvarchar(50) '$.info.name', lastName nvarchar(50) '$.info.surname',  
        age int, dateOfBirth datetime2 '$.dob') 

当JSON数据中包含数组时，例如：

DECLARE @json NVARCHAR(MAX)
SET @json =  
N'[  
       { "id" : 2,"info": { "name": "John", "surname": "Smith" }, 
         "Phones": ["123","345","678"] // like here
        }   
]' 

是否有任何方法可以连接解析数据上的数组以获得如下内容：

 Id     First Name      Last Name    Phone
 2      John            Smith        123
 2      John            Smith        345
 2      John            Smith        678

DECLARE @json NVARCHAR(MAX)
SET @json =  
N'[  
    { "id" : 2,"info": { "name": "John", "surname": "Smith" }, "Phones": ["123","345","678"] },
    { "id" : 3,"info": { "name": "Jane", "surname": "Smith" }, "Phones": ["321","543"] }
]';

WITH CTE AS (
    SELECT id, firstName, lastName, phones
    FROM OPENJSON(@json)
    WITH (
        id INT 'strict $.id',  
        firstName NVARCHAR(50) '$.info.name', 
        lastName NVARCHAR(50) '$.info.surname',
        phones NVARCHAR(MAX) '$.Phones' AS JSON
    )
)
SELECT c.id, c.firstName, c.lastName, p.value as phone
FROM CTE c
    CROSS APPLY OPENJSON(c.phones) p

SELECT ID,  FirstName, LastName, value 
FROM OPENJSON(@json)
WITH(ID int '$.id', 
     FirstName nvarchar(50) '$.info.name',
     LastName nvarchar(50) '$.info.surname',
     Phones nvarchar(max) '$.Phones' AS Json)
CROSS APPLY OPENJSON(Phones)

---

OUTER APPLY

是您的朋友。让我们把这两种行混在一起，以便更好地衡量

DECLARE @json NVARCHAR(MAX)
SET @json = N'
[
  {
    "id": 2,
    "info": {
      "name": "John",
      "surname": "Smith"
    },
    "age": 25,
    "Phones": [
      "123",
      "345",
      "678"
    ]
  },
  {
    "id": 5,
    "info": {
      "name": "Jane",
      "surname": "Smith"
    },
    "dob": "2005-11-04T12:00:00"
  }
]'  

SELECT id, [name], [surname], age, dateOfBirth, number
FROM (
    SELECT * 
    FROM OPENJSON(@json)
    WITH (
        id          INT             'strict $.id',
        [name]      NVARCHAR(50)    '$.info.name',
        [surname]   NVARCHAR(50)    '$.info.surname',
        age         INT,
        dateOfBirth DATETIME2       '$.dob',
        Phones      NVARCHAR(MAX)   AS JSON
    )
) AS people
OUTER APPLY OPENJSON(Phones)
WITH (
    number NVARCHAR(50) '$'
)

结果:

+----+------+---------+------+-----------------------------+--------+
| id | name | surname | age  |         dateOfBirth         | number |
+----+------+---------+------+-----------------------------+--------+
|  2 | John | Smith   | 25   | NULL                        | 123    |
|  2 | John | Smith   | 25   | NULL                        | 345    |
|  2 | John | Smith   | 25   | NULL                        | 678    |
|  5 | Jane | Smith   | NULL | 2005-11-04 12:00:00.0000000 | NULL   |
+----+------+---------+------+-----------------------------+--------+

---

您必须分两次完成：

提取每个人的数据并将电话号码数组保留为JSON

使用CROSS/OUTER APPLY解析每个人的电话号码数组，并将结果连接在一起

大概是这样的：

 Id     First Name      Last Name    Phone
 2      John            Smith        123
 2      John            Smith        345
 2      John            Smith        678

DECLARE @json NVARCHAR(MAX)
SET @json =  
N'[  
    { "id" : 2,"info": { "name": "John", "surname": "Smith" }, "Phones": ["123","345","678"] },
    { "id" : 3,"info": { "name": "Jane", "surname": "Smith" }, "Phones": ["321","543"] }
]';

WITH CTE AS (
    SELECT id, firstName, lastName, phones
    FROM OPENJSON(@json)
    WITH (
        id INT 'strict $.id',  
        firstName NVARCHAR(50) '$.info.name', 
        lastName NVARCHAR(50) '$.info.surname',
        phones NVARCHAR(MAX) '$.Phones' AS JSON
    )
)
SELECT c.id, c.firstName, c.lastName, p.value as phone
FROM CTE c
    CROSS APPLY OPENJSON(c.phones) p

SELECT ID,  FirstName, LastName, value 
FROM OPENJSON(@json)
WITH(ID int '$.id', 
     FirstName nvarchar(50) '$.info.name',
     LastName nvarchar(50) '$.info.surname',
     Phones nvarchar(max) '$.Phones' AS Json)
CROSS APPLY OPENJSON(Phones)

---

嗯，你总是可以这样做：

 Id     First Name      Last Name    Phone
 2      John            Smith        123
 2      John            Smith        345
 2      John            Smith        678

DECLARE @json NVARCHAR(MAX)
SET @json =  
N'[  
    { "id" : 2,"info": { "name": "John", "surname": "Smith" }, "Phones": ["123","345","678"] },
    { "id" : 3,"info": { "name": "Jane", "surname": "Smith" }, "Phones": ["321","543"] }
]';

WITH CTE AS (
    SELECT id, firstName, lastName, phones
    FROM OPENJSON(@json)
    WITH (
        id INT 'strict $.id',  
        firstName NVARCHAR(50) '$.info.name', 
        lastName NVARCHAR(50) '$.info.surname',
        phones NVARCHAR(MAX) '$.Phones' AS JSON
    )
)
SELECT c.id, c.firstName, c.lastName, p.value as phone
FROM CTE c
    CROSS APPLY OPENJSON(c.phones) p

SELECT ID,  FirstName, LastName, value 
FROM OPENJSON(@json)
WITH(ID int '$.id', 
     FirstName nvarchar(50) '$.info.name',
     LastName nvarchar(50) '$.info.surname',
     Phones nvarchar(max) '$.Phones' AS Json)
CROSS APPLY OPENJSON(Phones)

希望这有帮助。

您可以使用C#library

---

它是一个功能强大的工具，如果Json具有嵌套级别，它可以维护Json中的sql关系

伟大的解决方案，我被困在这个

电话NVARCHAR（MAX）作为JSON的问题上，所以实现了它像值一样clause@TheGameiswar：如果严格限制（和/或已知）值的数量，则从数组中显式提取它们可能比第二次
OPENJSON
要快。但是我没有任何计时JSON解析的经验，所以现在还不需要优化。：-）是的，你是对的，刚刚看到了执行计划，原始Json的成本为0，外部应用下面的Json的成本为20