c# - Entity framework map column which is not in old database -

i have table in new db contains column 'note'. have old db same table same structure have not column 'note'. changed edmx, added (mapped) column 'note' new db. if want use edmx in old db have error: column doest not exists...

i try put code try catch, without succesfull. error outside off try catch.

//---new version db                 try                 {                     vehicles = entities.vehicle.where(v => v.numplate == numplate || v.note == numplate);                 }                 catch (exception)                 {                     vehicles = entities.vehicle.where(v => v.numplate == numplate);                 }                 //---old version db                  foreach (vehicle vehicle in vehicles) //<------- error 

how can resolve? thanks

that's kind of 'hack', can choose ignore note property once you're using old database.

look onmodelcreating method in context class, , replace with:

    protected override void onmodelcreating(dbmodelbuilder modelbuilder)     {         if (this.database.connection.database == "name_of_old_database")             modelbuilder.entity<vehicle>().ignore(x => x.note);     } 

update:

since you're using .edmx mapping , there's no way modify mapping in runtime assume suggestion indeed wrong.

i still don't trying achieve using try/catch block, doesn't matter whether include (missing) note field in query or not, since entity framework realizes model no longer compatible database, refuse work database altogether.

but 2 points keep in mind:

• since you're using iqueryable, try/catch indeed in wrong place, exception thrown during materialization (when trying retrieving data).

  you can materialize query using tolist method (among others):

  entities.vehicle.where(v => v.numplate == numplate || v.note == numplate).tolist();

  or move try/catch block wrap foreach statement.

• you can use system.data.entity.database.compatiblewithmodel() method determine (upon context initialization example) whether model , database can still work together.