How to get data from json column in mssql - sql

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'