JSON Path Filter Expression SQL Server - json

Question

I have below JSON. I was trying to construct a query to fetch the FirstName, LastName, Iphone Number and Home Number. I am trying to use JSON Path filter expression. Its not working for me.
{
"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"
}
]
}
Query used
DECLARE #jsonInfo NVARCHAR(MAX)
SET #jsonInfo=N'{
"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
JSON_VALUE(#jsonInfo,'$.firstName') AS FirstName,
JSON_VALUE(#jsonInfo,'$.lastName') AS LastName
--JSON_VALUE(#jsonInfo,'$.phoneNumbers[?(#.type=="iPhone")].number') AS IPhoneNumber,
--JSON_VALUE(#jsonInfo,'$.phoneNumbers[?(#.type=="home")].number') AS HomeNumber
Regards
Amirtharaj

Answer 1

One way to parse this JSON is with OPENJSON() and explicit schema. phoneNumbers is a JSON array, so you need an additional OPENSJON() call.
SELECT
j1.firtstName, j1.lastName, j1.streetAddress, j1.city, j1.postalCode,
j2.*
FROM OPENJSON(#jsonInfo) WITH (
firtstName varchar(100) '$.firstName',
lastName varchar(100) '$.lastName',
streetAddress varchar(100) '$.address.streetAddress',
city varchar(100) '$.address.city',
postalCode varchar(100) '$.address.postalCode',
phoneNumbers nvarchar(max) '$.phoneNumbers' AS JSON
) j1
CROSS APPLY (
SELECT
MAX(CASE WHEN [type] = 'iPhone' THEN [number] END) AS iPhone,
MAX(CASE WHEN [type] = 'home' THEN [number] END) AS home
FROM OPENJSON(j1.phoneNumbers) WITH (
type varchar(10) '$.type',
number varchar(20) '$.number'
)
) j2
Result:
firtstName lastName streetAddress city postalCode iPhone ome
John doe naist street Nara 630-0192 0123-4567-8888 0123-4567-8910
Of course, you can extract each phone number from $.phoneNumbers JSON array using $.phoneNumbers[x].number as path expression (x is zero-based index):
SELECT
j1.firtstName, j1.lastName, j1.streetAddress, j1.city, j1.postalCode,
j1.number1, j1.number2
FROM OPENJSON(#jsonInfo) WITH (
firtstName varchar(100) '$.firstName',
lastName varchar(100) '$.lastName',
streetAddress varchar(100) '$.address.streetAddress',
city varchar(100) '$.address.city',
postalCode varchar(100) '$.address.postalCode',
number1 varchar(100) '$.phoneNumbers[0].number',
number2 varchar(100) '$.phoneNumbers[1].number'
) j1