reading JSON values .. in SQL 2012 - json

Question

I have a SQL Server 2012 table with a column as per:
ResponseJSON varchar(max)
It contains text values like
{
"partNumber": 1,
"partTotal": 1,
"payeeLocationId": "ABC00011",
"remittanceAdviceId": "77592",
"paymentInfo": {
"accountInfo": {
"accountName": "ABC Hospital",
"xyzNumber": "",
"xyzCode": ""
},
"depositAmount": "1234",
"paymentReference": "ERA 1234"
},
"paymentRun": {
"payerName": "ABC",
"runDate": "2022-12-05"
},
"claimSummary": [
{
"benefit": "5555",
"channelCode": "ABC",
"claimId": "1234",
"lodgementDate": "2022-02-14",
"transactionId": "xpxpxpxpxxp",
"accountReferenceId": "12345678"
}
]
}
I wondered how to read the remittanceAdviceId value of 77592 (in this case) out of this JSON column data ..
The remittanceAdviceId may be varying size in length .. e.g. 1,2,3,4,5,6,7 etc digits
I considered something like :
SELECT remittanceAdviceId = CASE
WHEN E.RequestJSON IS NOT NULL AND
CHARINDEX('"remittanceAdviceId"', E.RequestJSON, 0) > 0 THEN
SUBSTRING(E.RequestJSON,
CHARINDEX('"remittanceAdviceId"', E.RequestJSON, 0) + 22,
5)
ELSE
NULL
END
but this isn't quite right as value may be other than 5 digits ..

Answer 1

Assuming upgrading to the latest version of SQL isn't in the cards right now, here's a simple approach using SUBSTRING and CHARINDEX:
DECLARE #json varchar(2000) = '{
"partNumber": 1,
"partTotal": 1,
"payeeLocationId": "ABC00011",
"remittanceAdviceId": "77592",
"paymentInfo": {
"accountInfo": {
"accountName": "ABC Hospital",
"xyzNumber": "",
"xyzCode": ""
},
"depositAmount": "1234",
"paymentReference": "ERA 1234"
},
"paymentRun": {
"payerName": "ABC",
"runDate": "2022-12-05"
},
"claimSummary": [
{
"benefit": "5555",
"channelCode": "ABC",
"claimId": "1234",
"lodgementDate": "2022-02-14",
"transactionId": "xpxpxpxpxxp",
"accountReferenceId": "12345678"
}
]
}';
SELECT SUBSTRING (
#json
, CHARINDEX ( '"remittanceAdviceId": "', #json, 0 ) + 23
, CHARINDEX ( '",', #json, CHARINDEX ( '"remittanceAdviceId": "', #json, 0 ) ) - CHARINDEX ( '"remittanceAdviceId": "', #json, 0 ) - 23
) AS remittanceAdviceId;
RETURNS
+--------------------+
| remittanceAdviceId |
+--------------------+
| 77592 |
+--------------------+
NOTES
Assumes valid JSON with quoted values.
There is no need to specify a length for the remittance id. It
will get parsed accordingly.
UPDATE
Now that you know you can use the native JSON feature in SQL, the simplest way to extract a single value from JSON is:
SELECT JSON_VALUE ( #json, '$.remittanceAdviceId' ) AS remittanceAdviceId;
RETURNS
+--------------------+
| remittanceAdviceId |
+--------------------+
| 77592 |
+--------------------+