Linq Dynamic query for getting dynamic list based on Id

I have created the Dynamic Model list.Here i need to get Dynamic list based on id.so I have tried the code. but i didn't get correct result.please help to get that

 

code:

 

public virtual List GetAll(long index=0,string FieldName="")

{

try

{

_context.Set().SelectByName(FieldName).Distinct();

}

catch (Exception exc)

{

IsError = true;

ErrorMessage = exc.ToString();

Status = "Sorry,Not taken the Details";

}

return null;

}

public static IQueryable SelectByName(this IQueryable source,

string FieldName)

{

ParameterExpression paramExp = Expression.Parameter(typeof(T), "x");

ConstantExpression valueexp = Expression.Constant(value);

MemberExpression memberExp = Expression.PropertyOrField(paramExp, FieldName);

var lambdaExp = Expression.Lambda>(memberExp, paramExp);

return source.Select(lambdaExp);

}