ReferenceMap not mapping correctly

[abhilashca]

Hello,

I integrated Dapper.Extensions into an existing project recently. And, I was trying to map data of the child item via ReferenceMap. For some reason, it is not mapping as expected. I have gone through the test case provided but was unable to make it working.

Here is how my code snippet looks like:

// User Group Member class
public class UserGroupMember
{
    public int UserGroupMemberId { get; set; }   // Primary Key
    public int UserGroupId { get; set; }
    public int UserId { get; set; }

    // Type I am trying to map.
    public User UserInstance { get; set; }
}

// User class
public class User
{
    public int UserId { get; set; }    // Primary Key
    public string FirstName { get; set; }        
    public string LastName { get; set; }
}

// User Group Member Class Mapper
public class UserGroupMemberMapper : ClassMapper<UserGroupMember>
{
    public UserGroupMemberMapper()
    {
        TableName = "UserGroupMember";

        Map(m => m.UserInstance).Ignore();
        AutoMap();

        ReferenceMap(m => m.UserInstance).Reference<User>((u, gm) => u.UserId == gm.UserId);
    }
}

When I load group member collection, UserInstance is always returning null.

Any idea what I am missing here? Any help will be appreciated.

Thank you.

[abhilashca]

@valfrid-ly I have gone through the test case explaining reference map. However, I am unable to make it working. Do you have any thoughts on why it's not working?

[valfrid-ly]

Sorry for the delay @abhilashca , you need to also create a map to the User class, so it'll find the table.

Please test it and follow up with me.

[abhilashca]

Thank you @valfrid-ly. Much appreciated for the reply. Let me try the same and will keep you posted.

[a-priestley]

Hi again, I'm having trouble comprehending what needs to be done. Is there any way you have time to provide a fleshed-out example? I am also attempting to accomplish joins but to no avail.. Is the OP's first Mapper correct?

If so, then the second mapper could be like so:

Table("UserInstance")
AutoMap();

My example has explicit properties but the references don't resolve. If I do var mapper = await DapperAsyncExtensions.GetMap<User>();

mapper.References is empty.