SQL Server : I want to access Json Array of object - sql-server

Question

DECLARE #json varchar(max),
#errors varchar(max),
#policy_number varchar(10)
SET #json =
'{
"returnMessage": "",
"policy_number": "12345",
"documents": {
"policy_document": "",
"tax_invoice_document": ""
},
"errors": [
{
"error_code": "999",
"error_message1": "Error"
}
]
}'
I want to get Error_code, error_message1
SELECT
#policy_number = policy_number,
#errors = errors
FROM
OPENJSON(#json) WITH
(
policy_number VARCHAR(10) '$.policy_number',
errors VARCHAR(max) '$.errors'
)

Answer 1

If you only want data from the errors property, you can go straight to that with a single OPENJSON call
DECLARE #json varchar(max)
SET #json =
'{
"returnMessage": "",
"policy_number": "12345",
"documents": {
"policy_document": "",
"tax_invoice_document": ""
},
"errors": [
{
"error_code": "999",
"error_message1": "Error"
}
]
}'
SELECT
policy_number = JSON_VALUE(#json, '$.policy_number'),
error_code,
error_message1
FROM
OPENJSON(#json, '$.errors')
WITH (
error_code VARCHAR(100),
error_message1 VARCHAR(100)
);

Answer 2

You're close. You need AS JSON in your OPENJSON and then you can use CROSS APPLY to pull your desired values out of errors.
declare #json varchar(max),#errors varchar(max),#policy_number varchar(10)
set #json =
'{
"returnMessage": "",
"policy_number": "12345",
"documents": {
"policy_document": "",
"tax_invoice_document": ""
},
"errors": [
{
"error_code": "999",
"error_message1": "Error"
}
]
}';
SELECT error_code, error_message1
FROM OPENJSON(#json)
WITH (errors NVARCHAR(MAX) AS JSON) l1
CROSS APPLY OPENJSON(l1.errors)
WITH (
error_code VARCHAR(100),
error_message1 VARCHAR(100)
);