Json query to a table? - json

Question

I have a JSON string as shown below. How can I create a table below or similar using SQL Server with a procedure or function? Thanks all.
I'm using SQL Server 15.0.2080.9.
{
"Person": {
"firstName": "John",
"lastName": "Smith",
"age": 25,
"Address": {
"streetAddress":"21 2nd Street",
"city":"New York",
"state":"NY",
"postalCode":"10021"
},
"PhoneNumbers": {
"home":"212 555-1234",
"fax":"646 555-4567"
}
}
}

Answer 1

An excellent starting point is this Q&A, but a simplified approach (if the parsed JSON has a variable structure with nested JSON objects, but without JSON arrays) is the folowing recursive statement:
JSON:
DECLARE #json nvarchar(max) = N'
{
"Person": {
"firstName": "John",
"lastName": "Smith",
"age": 25,
"Address": {
"streetAddress":"21 2nd Street",
"city":"New York",
"state":"NY",
"postalCode":"10021"
},
"PhoneNumbers": {
"home":"212 555-1234",
"fax":"646 555-4567"
}
}
}'
Statement:
;WITH rCTE AS (
SELECT
1 AS Id,
CONVERT(nvarchar(max), NULL) COLLATE DATABASE_DEFAULT AS [Parent],
CONVERT(nvarchar(max), N'Person') COLLATE DATABASE_DEFAULT AS [Key],
CONVERT(nvarchar(max), JSON_QUERY(#json, '$.Person')) COLLATE DATABASE_DEFAULT AS [Value]
UNION ALL
SELECT
r.Id + 1,
CONVERT(nvarchar(max), r.[Key]) COLLATE DATABASE_DEFAULT,
CONVERT(nvarchar(max), c.[Key]) COLLATE DATABASE_DEFAULT,
CONVERT(nvarchar(max), c.[value]) COLLATE DATABASE_DEFAULT
FROM rCTE r
CROSS APPLY OPENJSON(r.[Value]) c
WHERE ISJSON(r.[Value]) = 1
)
SELECT [Parent], [Key], [Value]
FROM rCTE
ORDER BY Id
Result:
Parent
Key
Value
Person
{"firstName": "John", "lastName": "Smith", "age": 25, "Address": {"streetAddress":"21 2nd Street", "city":"New York", "state":"NY", "postalCode":"10021"}, "PhoneNumbers": {"home":"212 555-1234", "fax":"646 555-4567" }}
Person
firstName
John
Person
lastName
Smith
Person
age
25
Person
Address
{"streetAddress":"21 2nd Street", "city":"New York", "state":"NY", "postalCode":"10021"}
Person
PhoneNumbers
{"home":"212 555-1234", "fax":"646 555-4567"}
PhoneNumbers
home
212 555-1234
PhoneNumbers
fax
646 555-4567
Address
streetAddress
21 2nd Street
Address
city
New York
Address
state
NY
Address
postalCode
10021

Answer 2

You can use Openjson, it would give you your desired result.
this is an example for your specific JSON:
DECLARE #Json NVARCHAR(max) = '{
"Person": {
"firstName": "John",
"lastName": "Smith",
"age": 25,
"Address": {
"streetAddress":"21 2nd Street",
"city":"New York",
"state":"NY",
"postalCode":"10021"
},
"PhoneNumbers": {
"home":"212 555-1234",
"fax":"646 555-4567"
}
}
}'
SELECT NULL AS Parent
,[KEY]
,[value]
FROM openjson(#json, '$')
UNION ALL
SELECT 'Person' AS Parent,
[KEY]
,[value]
FROM openjson(#json, '$.Person')
UNION ALL
SELECT 'Address'AS Parent,
[KEY]
,[value]
FROM openjson(#json, '$.Person.Address')
UNION ALL
SELECT 'PhoneNumbers' AS Parent ,[KEY]
,[value]
FROM openjson(#json, '$.Person.PhoneNumbers')