Accessing JSON Array in SQL Server 2016 using JSON_VALUE

问题

I am stuck while accessing array inside json using newly introduced JSON_VALUE function. Please consider following code -

IF EXISTS(SELECT 1 FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME='JsonData')
    DROP TABLE JsonData;
go

CREATE TABLE JsonData(JsonData nvarchar(max));
DECLARE @SQL nvarchar(max);
DECLARE @Table AS TABLE(JsonPath VARCHAR(256));

INSERT INTO JsonData(JsonData)
VALUES(
'{
  "firstName": "John",
  "lastName" : "doe",
  "age"      : 26,
  "address"  : {
    "streetAddress": "naist street",
    "city"         : "Nara",
    "postalCode"   : "630-0192"
  },
  "phoneNumbers": [
    {
      "type"  : "iPhone",
      "number": "0123-4567-8888"
    },
    {
      "type"  : "home",
      "number": "0123-4567-8910"
    }
  ]
}')


INSERT INTO @Table
SELECT VALUE  FROM OPENJSON('{
"Path1":"$.firstName","Path2":"$.phoneNumbers[:1].number"
}') ;

SELECT  @SQL=(SELECT 'UNION SELECT '''+ CAST(JsonPath AS VARCHAR(256)) +''',JSON_VALUE(JsonData,'''+a.JsonPath+''')  
                    FROM JsonData a'                             
                    FROM @Table a       
        FOR XML PATH(''), TYPE)
    .value('.','NVARCHAR(MAX)')
FROM @Table t;

SELECT @SQL=RIGHT(@SQL,LEN(@SQL)-5)

PRINT @SQL    

EXEC SP_EXECUTESQL @SQL;

Here If I want to access specific phone number then usual syntax of accessing this node is not working. I am getting following error in this case

JSON path is not properly formatted. Unexpected character ':' is found at position 15.

Though when I checked at http://jsonpath.com , I am able to retrieve value. Does SQL server 2016 uses some different syntax for accessing JSON values?

回答1:

To get all from phoneNumbers:

DECLARE @json nvarchar(max)=
    '{
      "firstName": "John",
      "lastName" : "doe",
      "age"      : 26,
      "address"  : {
        "streetAddress": "naist street",
        "city"         : "Nara",
        "postalCode"   : "630-0192"
      },
      "phoneNumbers": [
        {
          "type"  : "iPhone",
          "number": "0123-4567-8888"
        },
        {
          "type"  : "home",
          "number": "0123-4567-8910"
        }
      ]
    }'

    SELECT [Type], [Number]
    FROM OPENJSON( @json, '$.phoneNumbers' ) 
    WITH ([Type] NVARCHAR(25) '$.type', [Number] NVARCHAR(25) '$.number');

回答2:

You can use "CROSS APPLY" to get the phone numbers with firstName:

SELECT  JSON_VALUE (jsonData, '$.firstName'),p.*
    FROM JsonData
    CROSS APPLY
    OPENJSON (JsonData, '$.phoneNumbers') WITH(type varchar(10) '$.type', number varchar (30) '$.number') p

回答3:

SQL Server 2016 supports JSON. It's very similar, almost identical. You'll make your own comparison.

You don't need to use a temp variable @Table and then make manipulations...

Simply run the following queries

SELECT  JSON_VALUE( JsonData, '$.phoneNumbers[0].type' ) AS [PhoneType], 
        JSON_VALUE( JsonData, '$.phoneNumbers[0].number' ) AS [PhoneNumber]
FROM JsonData
WHERE ISJSON( JsonData ) > 0;
--iPhone 0123-4567-8888

SELECT  JSON_VALUE( JsonData, '$.phoneNumbers[1].type' ) AS [PhoneType], 
        JSON_VALUE( JsonData, '$.phoneNumbers[1].number' ) AS [PhoneNumber]
FROM JsonData
WHERE ISJSON( JsonData ) > 0;
--home  0123-4567-8910

Check out these official links from Microsoft, about JSON support for more details:

https://msdn.microsoft.com/en-us/library/dn921897.aspx

https://msdn.microsoft.com/en-us/library/dn921898.aspx

回答4:

All together.

DECLARE @json NVARCHAR(MAX)
    = '{
      "firstName": "John",
      "lastName" : "doe",
      "age"      : 26,
      "address"  : {
        "streetAddress": "naist street",
        "city"         : "Nara",
        "postalCode"   : "630-0192"
      },
      "phoneNumbers": [
        {
          "type"  : "iPhone",
          "number": "0123-4567-8888"
        },
        {
          "type"  : "home",
          "number": "0123-4567-8910"
        }
      ]
    }';

SELECT
    Core.*
   ,ARRAY.[Type]
   ,ARRAY.[Number]
FROM
    OPENJSON(@json)
        WITH
        (
            FirstName NVARCHAR(25) '$.firstName'
           ,LastName NVARCHAR(25) '$.lastName'
           ,Age INT '$.age'
           ,streetAddress NVARCHAR(25) '$.address.streetAddress'
           ,city NVARCHAR(25) '$.address.city'
        ) AS Core
    CROSS APPLY
    OPENJSON(@json, '$.phoneNumbers')
        WITH
        (
            [Type] NVARCHAR(25) '$.type'
           ,[Number] NVARCHAR(25) '$.number'
        ) AS ARRAY;

来源：https://stackoverflow.com/questions/38285223/accessing-json-array-in-sql-server-2016-using-json-value