How can recognize a custom field programmatically?

Question

In Microsoft Dynamics 365, I need to find custom fields in an entity, I want to get custom fields of an entity with odata(rest api) or with SDK for dynamic purpose. Is there any way to find out as programmatically method?

Answer 1

You can easily enumerate the customization prefixes of all publishers in your instance by querying the publisher table, you want the column named customizationprefix .

Once you have retrieved all the prefixes, you can filter the result of a RetrieveEntityRequest to extract all the columns where the name starts with "<customizationprefix>_" .

Prefixes like adx , cc and msdyn come from add-ons (Portal, Marketing, Field Service etc.), you might want to cherry pick the list of prefixes depending on your specific needs.

Sample code:

var client = new CrmServiceClient( /* ... */ );
const string ENTITY_TO_CHECK = "account";   // logical name

var prefixesQuery = new QueryExpression("publisher") { 
  ColumnSet = new ColumnSet("customizationprefix")
};
var prefixesData = client.RetrieveMultiple(prefixesQuery).Entities
  ?.Select(e => e.GetAttributeValue<string>("customizationprefix"));

Console.WriteLine("Publisher prefixes:");
foreach (var pd in prefixesData)
  Console.WriteLine("> {0}", pd);

var columnsQuery = new RetrieveEntityRequest
{
  LogicalName = ENTITY_TO_CHECK,
  EntityFilters = EntityFilters.Attributes,
  RetrieveAsIfPublished = true
};

var columnsData = (client.Execute(columnsQuery) as RetrieveEntityResponse)?.EntityMetadata?.Attributes
  ?.Where(col => prefixesData.Any(prefix => col.LogicalName.StartsWith($"{prefix}_")))
  .OrderBy(col => col.LogicalName);

Console.WriteLine("{0} custom fields: {1}", ENTITY_TO_CHECK, columnsData.Count());
foreach (var cd in columnsData.Take(1))
  Console.WriteLine("> {0}", cd.LogicalName);

Console.ReadLine();