How to use HTTP Post method in SAP Gateway Client using JSON format?

[bigflatfoot]

I was trying to update a custom table using the HTTP METHOD POST in SAP Gateway Client. Here's the JSON format that I've used. The fields ZBANDNAME, ZESTDATE, ZMEMBERS are key fields while the ZSTATUS is not and I'm trying to update it.

{
 "ZBANDNAME" : "ONE DIRECTION",
 "ZESTDATE" : "2010",
 "ZMEMBERS" : "FOUR",
 "ZSTATUS"  : "DISBANDED"
}

Upon trying to update the value of a field ZSTATUS in SAP GW Client, I encountered an error message: "The key value is already in use. Please enter a different one."  

How can I avoid this issue and proceed with the update?

[Sandra_Rossi]

In OData standards, the POST method is used to create, not to update.

[bigflatfoot]

@Sandra_Rossi thank you. However, I am experiencing an error 400 code when using the PATCH, or DELETE HTTP Method. Would that be related to authorization issue?

[Sandra_Rossi]

You need to change the URL to pass the key (it's like GET). PATCH serviceRoot/entity(key). See how OData works.

[ArunJacob]

Hi,

Which is the key filed in this?

The error suggests that you're trying to update an existing record. Apart from the key field, can you please modify the values of other properties and try?

PATCH or PUT instead of CREATE you can try, also please ensure the correct Url.

Thanks