如何从 mssql 中的 json 列获取数据

Question

I'm struggling to write a query that gets value from json column with some specific conditions. I have a table named Table1 with a column of type nvarchar(max) named Data that contains some json values. The json itself looks like this:

{
"Addresses": [
    {
        "ApartmentNumber": "1",
        "City": "Rome",
        "CountryCode": "IT",
        "HouseNumber": "2",
        "Post": "Rome",
        "PostalCode": "11-111",
        "Region": "Rome",
        "Street": "Italian",
        "StreetPrefix": "St.",
        "TypeCode": "PERMANENT"
    },
    {
        "ApartmentNumber": "11",
        "City": "Madrid",
        "CountryCode": "ES",
        "HouseNumber": "22",
        "Post": "Madrid",
        "PostalCode": "11-111",
        "Region": "Madrid",
        "Street": "Spanish",
        "StreetPrefix": "St.",
        "TypeCode": "CORRESPONDENCE"
    }
],
"Contacts": [
    {
        "TypeCode": "EMAIL",
        "DefaultContact": false,
        "Value": "sample@xyz.com"
    }
],
"PersonData": {
    "BirthDate": "1968-08-03T00:00:00",
    "CitizenshipCode": "US",
    "DeathDate": "0001-01-01T00:00:00",
    "FirstName": "John",
    "Gender": "M",
    "LastName": "Jones"
}

}

I would like to get a value of CountryCode from the Addresses node where TypeCode is "CORRESPONDENCE". I tried to achieve that with combinations of JSON_VALUE and JSON_QUERY functions but I failed. Below are some examples of my trials:

query:

SELECT JSON_QUERY(t.Data, '$.Addresses') AS Address FROM [Table1] t

result:

[
{
    "ApartmentNumber": "1",
    "City": "Rome",
    "CountryCode": "IT",
    "HouseNumber": "2",
    "Post": "Rome",
    "PostalCode": "11-111",
    "Region": "Rome",
    "Street": "Italian",
    "StreetPrefix": "St.",
    "TypeCode": "PERMANENT"
},
{
    "ApartmentNumber": "11",
    "City": "Madrid",
    "CountryCode": "ES",
    "HouseNumber": "22",
    "Post": "Madrid",
    "PostalCode": "11-111",
    "Region": "Madrid",
    "Street": "Spanish",
    "StreetPrefix": "St.",
    "TypeCode": "CORRESPONDENCE"
}

]

or this:

query:

 select top 1 JSON_VALUE(t.Data, '$.PersonData.LastName') FROM [Table1] t where ISJSON(t.Data) > 0 and JSON_VALUE(pd.BusinessPartner, '$.PersonData.Gender') = 'F'

result: "Jones"

but when i to write similar query with Addresses as condition:

query:

  select top 1 JSON_VALUE(t.Data, '$.Addresses.CountryCode') FROM [Table1] t where ISJSON(t.Data) > 0 and JSON_VALUE(t.Data,'$.Addresses.TypeCode') = 'CORRESPONDENCE'

I get empty string as the result.

Thanks in advance

Answer 1

From SQL Server 2016, you can query on JSON column. See the documentation: Work with JSON data

The interesting part for you it's Analyze JSON data with SQL queries .

This done:

select Id, PostalCode
from Address
CROSS APPLY OPENJSON (Address.Data, N'$.Addresses')
WITH (
    TypeCode varchar(50) '$.TypeCode',
    PostalCode varchar(50) '$.PostalCode'
) AS AddressesJsonData
WHERE TypeCode  = N'PERMANENT'