How to map DataTable to DTO by using automapper

Question

I'm new to AutoMapper and have couple of questions regarding datatable to object mapping. I have sqlquery code and sql result. I want to do object to object map with automapper. any help's?

score 3 · Accepted Answer · answered Oct 10 '16 at 07:10

I guess it could go something like this (broad lines):

AutoMapper.Mapper.CreateMap<DataSet, CompanyModel>()
     .ForMember(m => m.Company, opt => opt.MapFrom(r => r.Tables[0].Columns["Company"]))
     .ForMember(m => m.Customers, opt => opt.MapFrom(r => r.Tables[0].Columns["Customers"]))
     .ForMember(m => m.Amount, opt => opt.MapFrom(r => Double.Parse(r.Tables[0].Columns["Amount"]));

and then

Mapper.Map<List<CompanyModel>>(ds);

Providing more details (code) would probably result in more precise answers.

I tried your code but Not WorkingError:An exception of type 'AutoMapper.AutoMapperMappingException' occurred in AutoMapper.dll but was not handled in user code. — Sai Kumar, Oct 12 '16 at 06:30

score 2 · Answer 2 · edited May 23 '17 at 11:45

Look here Convert DataRow to Object with AutoMapper

For now I did this based on above, so far I have only tested with flat DTO with Primitive types:

public class CustomResolver : IValueResolver
{
    public ResolutionResult Resolve(ResolutionResult source)
    {
        return source.New(Convert.ChangeType((source.Context.SourceValue as DataRow)[source.Context.MemberName], source.Context.DestinationType));
    }
}


public static class DtoTransformDataTable<T> where T : new()
{
    public static IEnumerable<T> JustDoIt(DataTable dt)
    {
        Mapper.CreateMap<DataRow, T>().ForAllMembers(m => m.ResolveUsing<CustomResolver>());
        var listOfT = new List<T>();

        foreach (var item in dt.Rows) //Use LINQ to concise
        {
            var dest = Mapper.Map<T>(item);
            listOfT.Add(dest);
        }
        return listOfT;
    }
}

Don't think that works with AutoMapper 5 - the IValueResolver interface has changed - https://github.com/AutoMapper/AutoMapper/wiki/5.0-Upgrade-Guide — David Gardiner, Feb 02 '17 at 03:38

score 0 · Answer 3 · answered Oct 12 '16 at 06:44

I don't think this is supported by Automapper out of the box if you are using plain untyped DataTables/DataSets.

However, if you create a typed DataTable/DataSet then things should work better. A typed DataSet gives your table rows properties for each column and should be easier to use with AutoMapper.

I haven't used typed DataSets in years, but they are still supported in .Net. Look here for some information on how to set them up.

How to map DataTable to DTO by using automapper

3 Answers3