Use linq or fetchxml query with dynamic entity list

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I'm building a .net console application to query certain crm records (8.2 on-prem) and save the field values to an xml file. For example I want to query a contact and get values from 20 fields. I'm using entity framework 6 and I created a db and table where one of the columns has the 20 fields names that I want to use in my query e.g. firstname, lastname, email, etc.. How can I use the list of fields that I get from my ef context/dbset in a linq query?

var context = new DBContext();
            foreach (var field in context.DBSet)
            {
                Console.WriteLine(field.CrmField);
            }

In code above, field.CrmField are all the field names that I'm trying to use in my linq query below:

var linq_query = from c in orgSvcContext.CreateQuery("contact")									 
									 where (String)c["trigger_field"] == "100000001"
									 select new
									 {
										//Instead of hardcoding these values, I'd like to use the list from ef above
										 contact_id = c["contactid"],										 
										 first_name = c["firstname"],
										 last_name = c["lastname"]
									 };
					foreach (var record in linq_query)
					{
						Console.WriteLine($"Linq: {record.first_name} {record.last_name} - contactid:{record.contact_id}");
					}

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Community Member on at

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Bump anyone?

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Kokulan 18,054 on at

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Hi

I do not normally use Linq as behind the scene it generates QueryExpression and if you do your query directly in query expression, you have full control over the query.

I would normally do this in similary scenario usign Query Expression

var context = new DBContext();

foreach (var field in context.DBSet)

{

Console.WriteLine(field.CrmField);

}

QueryExpression qe = new QueryExpression("contact");

qe.ColumnSet = new ColumnSet(context.DBSet.ToArray()); // Field names not hardcoded

.. Once you executed the RetrieveMultiple, you will get an Entity Collection, you can then covert that to / creeate any type of object you want from it really

Let me know more example on this

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Dynamics365 Rocker 7,755 on at

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You are using late binding, In this case, You can use FetchXML or query expression.

In console app,You can use early binding, Linq will be easy with Early binding.

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Community Member on at

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Thank you @Kokulan Eswaranathan. Can you provide a full code example? Much appreciated.

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Community Member on at

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Disregard, I was able to solve it with this:

string[] arrFields = context.dbset.Select(x => x.CrmField).ToArray();

And then in QueryExpression:

ColumnSet = new ColumnSet(arrFields)

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