Specially who is doing a CURD operation using Postman plugin using chrome browser has been resolved successfully please find the below step how to proceed..
1.Create a Odata service and expose a entity.
2.Copy the Specific URL which you exposed in Postman .
3.Provide a basic authentication.
4.Copy the format of code which you exposed in the json format as below example.
5.Before click on send content type should be–application/json;Charset=utf-8.