Querying inlineHelpText using the tooling API

Question

From my small experiments it seems that this field isn't queryable through the Tooling API.
Using this query here:

https://www.salesforce.com/services/data/v40.0/tooling/query?q=Select+Id,+DeveloperName,+inlineHelpText+from+FieldDefinition+where QualifiedApiName='Account'

This returns

[
    {
        "message": "\nSelect Id, DeveloperName, inlineHelpText from FieldDefinition\n                          ^\nERROR at Row:1:Column:27\nNo such column 'inlineHelpText' on entity 'FieldDefinition'. If you are attempting to use a custom field, be sure to append the '__c' after the custom field name. Please reference your WSDL or the describe call for the appropriate names.",
        "errorCode": "INVALID_FIELD"
    }
]

Skipping the inLineHelpText from the query returns results so it seems that I can't retrieve this field data. Has anyone run into this problem?

Answer 1

While "inlineHelpText" appears in the FieldDefintion docs it isn't in the context of a field on FieldDefinition. It appears under the CustomField Metadata. Which is the metadata you get on fields against other objects. Not against the FieldDefinition itself.

You can confirm this with the following Apex:

HttpRequest req = new HttpRequest();
req.setEndpoint(Url.getOrgDomainUrl().toExternalForm() + '/services/data/v44.0/tooling/sobjects/TraceFlag/describe/');
req.setMethod('GET');
req.setHeader('Authorization', 'Bearer ' + UserInfo.getSessionId());
Http h = new Http();
HttpResponse res = h.send(req);
system.debug(res.getBody());

That JSON that comes back from that describe is for what you can query about a FieldDefinition. You'll notice that inlineHelpText doesn't appear as the name of the field.

Instead it comes back as metadata on the FieldDefinition fields.

E.g. The Tooling API FieldDefinition.Id has a null value for the inlineHelpText.

So, in conclusion, if you want to see the inlineHelpText you do a describe on the sObject in question rather than looking directly at the FieldDefintion.