AutoMapper.Collection.EFCore

Automapper.Collection.EntityFrameworkCore will help you mapping of EntityFrameowrk Core DbContext-object.

Mapper.Initialize(cfg =>
{
    cfg.AddCollectionMappers();
    cfg.SetGeneratePropertyMaps<GenerateEntityFrameworkCorePrimaryKeyPropertyMaps<DB>>();
    // Configuration code
});

User defined equality expressions will overwrite primary key expressions.

What about comparing to a single existing Entity for updating?

Automapper.Collection.EntityFramework does that as well through extension method from of DbSet.

Translate equality between dto and EF object to an expression of just the EF using the dto's values as constants.

dbContext.Orders.Persist().InsertOrUpdate<OrderDTO>(newOrderDto);
dbContext.Orders.Persist().InsertOrUpdate<OrderDTO>(existingOrderDto);
dbContext.Orders.Persist().Remove<OrderDTO>(deletedOrderDto);
dbContext.SubmitChanges();

Note: This is done by converting the OrderDTO to Expression<Func<Order,bool>> and using that to find matching type in the database. You can also map objects to expressions as well.

Persist doesn't call submit changes automatically

How to get it

Use NuGet Package Manager to install the package or use any of the following command in NuGet Package Manager Console.

PM> Install-Package AutoMapper.Collection.EntityFrameworkCore