With Salesforce REST API sobjects how does one decide which ID is used?

Question

There is documentation on Salesforce website named "Introducing Lightning Platform REST API" and the link is the following:

https://developer.salesforce.com/docs/atlas.en-us.api_rest.meta/api_rest/dome_describeGlobal.htm

When I run a query similar in the example, but on "System__c" object like the following:

curl https://instance.salesforce.com/services/data/v42.0/sobjects/System__c -H "Authorization: Bearer ACTUAL_TOKEN" -H "X-PrettyPrint:1"

The output is the following:

    {
      "objectDescribe" : {
        "activateable" : false,
        "createable" : true,
        "custom" : true,
        "customSetting" : false,
        "deletable" : true,
        "deprecatedAndHidden" : false,
        "feedEnabled" : true,
        "hasSubtypes" : false,
        "isSubtype" : false,
        "keyPrefix" : "a01",
        "label" : "System",
        "labelPlural" : "Systems",
        "layoutable" : true,
        "mergeable" : false,
        "mruEnabled" : true,
        "name" : "System__c",
        "queryable" : true,
        "replicateable" : true,
        "retrieveable" : true,
        "searchable" : true,
        "triggerable" : true,
        "undeletable" : true,
        "updateable" : true,
        "urls" : {
          "compactLayouts" : "/services/data/v42.0/sobjects/System__c/describe/compactLayouts",
          "rowTemplate" : "/services/data/v42.0/sobjects/System__c/{ID}",
          "approvalLayouts" : "/services/data/v42.0/sobjects/System__c/describe/approvalLayouts",
          "defaultValues" : "/services/data/v42.0/sobjects/System__c/defaultValues?recordTypeId&fields",
          "describe" : "/services/data/v42.0/sobjects/System__c/describe",
          "quickActions" : "/services/data/v42.0/sobjects/System__c/quickActions",
          "layouts" : "/services/data/v42.0/sobjects/System__c/describe/layouts",
          "sobject" : "/services/data/v42.0/sobjects/System__c"
        }
      },
      "recentItems" : [ {
        "attributes" : {
          "type" : "System__c",
          "url" : "/services/data/v42.0/sobjects/System__c/b02f000000MCbLwAAL"
        },
        "Id" : "b02f000000MCbLwAAL",
        "Name" : "S000040"
      }, {
        "attributes" : {
          "type" : "System__c",
          "url" : "/services/data/v42.0/sobjects/System__c/b02f000000M3qsPAAR"
        },
        "Id" : "b02f000000M3qsPAAR",
        "Name" : "S000046"
      }, {
        "attributes" : {
          "type" : "System__c",
          "url" : "/services/data/v42.0/sobjects/System__c/b02f000000M3AQcAAN"
        },
        "Id" : "b02f000000M3AQcAAN",
        "Name" : "S000045"
      } ]
    }

Notice that the bottom of the JSON response has three URL's with different IDs:

    "Id" : "b02f000000MCbLwAAL",
    "Id" : "b02f000000M3qsPAAR",
    "Id" : "b02f000000M3AQcAAN",

To create a URL to access the data, it would have to look like: https://instance.salesforce.com/services/data/v42.0/sobjects/system__c/b02f000000MCbLwAAL

How do I determine which ID I need to use for the URL?

Answer 1

The endpoint you are hitting is performing a Describe call, which returns details about the object's definition, not its records. The response includes the Ids of a certain number of recently viewed records of this type. Notice that the enclosing key is 'recentItems'.

You can, if you wish, perform a query to obtain the data for any or all of these objects, but the endpoint that you are hitting is not performing a query against this object.

Answer 2

As David explained, those are the recently viewed records. I'm not going to repeat everything he said so look at his answer.

As far as which url to use, the answer is most likely none.

The response contains a list of end points for performing various actions:

 "urls" : {
  "compactLayouts" : "/services/data/v42.0/sobjects/System__c/describe/compactLayouts",
  "rowTemplate" : "/services/data/v42.0/sobjects/System__c/{ID}",
  "approvalLayouts" : "/services/data/v42.0/sobjects/System__c/describe/approvalLayouts",
  "defaultValues" : "/services/data/v42.0/sobjects/System__c/defaultValues?recordTypeId&fields",
  "describe" : "/services/data/v42.0/sobjects/System__c/describe",
  "quickActions" : "/services/data/v42.0/sobjects/System__c/quickActions",
  "layouts" : "/services/data/v42.0/sobjects/System__c/describe/layouts",
  "sobject" : "/services/data/v42.0/sobjects/System__c"
}

Most likely, you want to use one of these URLs.

As for which ID, your code should already have an object's ID or you should be obtaining that id using a different call (you can't rely on the recent items to contain the Id you're looking for). Then you simply append the ID to the endpoint for sobjects:

var endpoint = describeResponse.urls.sobject + '/' + record.Id;

that will get you the information for a specific record.

Documentation:

• Querying data
• Working with records documentation