How can I get the API Name of a related EntityDefinition?

Question

I'm trying to use Custom Metadata Types to specify some relationships between objects. So I started out by creating my Custom Metadata Type and adding a Metadata Relationship to an Entity Definition.

In implementing this approach, I ran into an interesting surprise. When I tried to get an object's describe based on DeveloperName, it didn't give me any data. If I have an object whose API Name is My_Object__c, the DeveloperName field contains My_Object.

MyMetadata__mdt mapping = [
    SELECT SObjectType__c, SObjectType__r.DeveloperName
    FROM MyMetadata__mdt LIMIT 1
];
system.debug(mapping.SObjectType__c); // yields 01I00000000xxxx
system.debug(mapping.SObjectType__r.DeveloperName); // yields My_Object
SObjectType s = Schema.getGlobalDescribe().get(mapping.SObjectType__r.DeveloperName);

Is there no way to get it to return the API Name in a way I can pass directly to describe methods? The same problem applies when I try to query a related Field Definition as well.

Answer 1

Both the EntityDefinition and FieldDefinition objects have a field called QualifiedApiName that does what I am looking for:

MyMetadata__mdt mapping = [
    SELECT SObjectType__r.QualifiedApiName
    FROM MyMetadata__mdt LIMIT 1
];
system.debug(mapping.SObjectType__r.QualifiedApiName); // yields My_Object__c
SObjectType s = Schema.getGlobalDescribe().get(mapping.SObjectType__r.QualifiedApiName);

When using this field, I can successfully retrieve describes in a dynamic manner.