How to return JSON property (SQL Server) - json

Question

I am trying to select some data that is stored as JSON in SQL Server.
When I run isjson on the string, it returns 1.
However, I am unable to parse it.
declare #testStr nvarchar(max) = '{"order":{"address":{"shipToAddLine1":"1234 ABC Dr","shipToCityStZip":"Washington, DC 00000"}}}'
select isjson(#testStr) -- returns 1
select json_value(#testStr, '$'). -- returns null
select json_value(#testStr, '$.order') -- returns null
select #testStr -- returns entire string
How do I select the order node from the test string #testStr?

Answer 1

You can't use JSON_VALUE because that is not a scalar value, you need to use JSON_QUERY instead. An example of a scalar value would be the shipToAddLine1 field: select json_value(#testStr, '$.order.address.shipToAddLine1').
Using JSON_QUERY to get the order would be:
select json_query(#testStr, '$.order')
Result:
{"address":{"shipToAddLine1":"1234 ABC Dr","shipToCityStZip":"Washington, DC 00000"}}

Answer 2

You can use JSON_VALUE(), JSON_QUERY() and OPENJSON() to parse the input JSON. It's important to mention the following:
Function JSON_QUERY extracts an object or an array from a JSON string. If the value is not an object or an array, the result is NULL in lax mode and an error in strict mode.
Function JSON_VALUE extracts a scalar value from a JSON string. If the path points to not a scalar value, the result is NULL in lax mode and an error in strict mode
When you want to parse JSON string and get results as table, use OPENJSON table-valued function.
If you need to extract the order key you have two options - JSON_QUERY() or OPENJSON(). The following statement demonstrates how to extract a JSON object (from $.order key) and JSON values (from $.order.address.shipToAddLine1 and $.order.address.shipToCityStZip keys):
DECLARE #testStr nvarchar(max) =
N'{
"order":{
"address":{
"shipToAddLine1":"1234 ABC Dr",
"shipToCityStZip":"Washington, DC 00000"
}
}
}'
-- or
SELECT
shipToAddLine1 = JSON_VALUE(#testStr, '$.order.address.shipToAddLine1'),
shipToCityStZip = JSON_VALUE(#testStr, '$.order.address.shipToCityStZip'),
[order] = JSON_QUERY(#testStr, '$.order')
SELECT shipToAddLine1, shipToCityStZip, [order]
FROM OPENJSON(#testStr) WITH (
shipToAddLine1 nvarchar(100) '$.order.address.shipToAddLine1',
shipToCityStZip nvarchar(100) '$.order.address.shipToCityStZip' ,
[order] nvarchar(max) '$.order' AS JSON
)
Result:
shipToAddLine1 shipToCityStZip order
1234 ABC Dr Washington, DC 00000 {
"address":{
"shipToAddLine1":"1234 ABC Dr",
"shipToCityStZip":"Washington, DC 00000"
}
}