c# - Apply a dynamically-built expression on non-generic DbSet -

i have following scenario:

• i have unknown @ compile time dbset, via type like:

  dbset entities = _repository.context.set(mytype) 

• i have dynamically-built expression of given type,

  expression myfilter; //built expression of mytype, constructed @ runtime

how can apply myfilter on entities, in order filter out entities based on myfilter?

below code might you: creates iqueryable of mytype represents select * yourmappedtable id = 1 of cource, instead of using expression have built demo purpose, use expression.

class program {     static void main(string[] args)     {         using (var x = new db01entities ())         {             type mytype = typeof(angajati);              var setmethod = typeof(db01entities).getmethods(system.reflection.bindingflags.instance | system.reflection.bindingflags.public).where (a => a.name == "set" && a.isgenericmethod).first ().getgenericmethoddefinition ();              var myset = setmethod.makegenericmethod(mytype);              var realset = myset.invoke(x, null);              var param1 = expression.parameter(mytype, "param1");              var propertyexpresion = expression.property(param1, "id");              var idexpresssion = expression.constant(1);              var body = expression.equal(propertyexpresion, idexpresssion);              var lambda = expression.lambda(body, param1);              var generictypecaster = typeof(program).getmethod("caster", system.reflection.bindingflags.static | system.reflection.bindingflags.nonpublic).getgenericmethoddefinition();              var effectivemethod = generictypecaster.makegenericmethod(mytype);              var filteredqueryable = effectivemethod.invoke(null, new object[] {realset, lambda });         }     }      private static iqueryable<t> caster <t> (dbset<t> theset, expression wherecondition) t : class     {         return theset.where(wherecondition expression<func<t, bool>>);     } } 

so "lambda" variable above equivalent "myfilter". must @ runtime

expression<func<yourtype, bool>>. 

and myset "entities' dbset. happy coding!