one-to-one association with string keys

Hi,

I have (in PostgreSQL) a table "Library" that has a primary key of type string named "library". I have a second table "LibrarySummary" that has a primary key of type string named "library". The two tables should really be one, but that's another story. Neither the Library nor the LibrarySummary table has a foreign key linking them, as their common primary keys can be used to do so.

I have created (in the LightSpeed designer) a one-to-one association from Library to LibrarySummary. I set the "Column Name" property of the association to "library", and changed the "Target Name" from the default "LibrarySummary" to "Summary".

I get a LightSpeedException:

"Unable to materialize field [SummaryId] on type [PostgreSQL.Model.Library]. Check your table has an Id column and that your mappings are correct. See inner exception for details."

The inner exception is:

"Index was outside the bounds of the array."

The stack trace is:

   at Mindscape.LightSpeed.LightSpeedException.€(Exception , String , Object[] )
   at Mindscape.LightSpeed.Model.FieldModel.Materialize(IDataProviderAdapter , Object , Object[] , Int32& )
   at Mindscape.LightSpeed.Mapping.EntityLoader.€(UnitOfWorkBase , String , Entity , Object[] ,  )
   at Mindscape.LightSpeed.Mapping.EntityLoader.LoadEntityFromReader(AliasedTypeModel , Object , Boolean )
   at ..€(AliasedTypeModel , QueryExpression , Order , Group , String , Boolean , Boolean )
   at ..€(LightSpeedContext , List`1 , QueryExpression , Order , Group , String , Boolean , Boolean )
   at ..€(AliasedTypeModel , IList , String , Boolean )
   at ..€(TypeModel , Query , IList )
   at ..€(UnitOfWorkBase , TypeModel , Query , IList )
   at ..€(Query , TypeModel , IList )
   at ..€(Query , IList )
   at Mindscape.LightSpeed.UnitOfWork.Find(Query query, IList results)
   at Mindscape.LightSpeed.UnitOfWorkBase.Find(Query query)
   at Mindscape.LightSpeed.Linq.Plan.SingleQueryPlan.ExecuteImmediate(IUnitOfWork unitOfWork, Type returnType)
   at Mindscape.LightSpeed.Linq.LinqQueryProvider.Execute(Expression expression)
   at Mindscape.LightSpeed.Linq.LinqQueryProvider.System.Linq.IQueryProvider.Execute(Expression expression)
   at Mindscape.LightSpeed.Linq.LinqQuery`1.GetEnumerator()
   at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
   at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)

I am using LightSpeed 4.0.646.18138.

I assume this has something to do with the Library table lacking an explicit FK to the LibrarySummary key, but I don't know how to set this up in LightSpeed.

thanks!
Derek

Hi Derek,

You need an explicit backing field for the the one to one association to store its data in, so setting this up as an association in the model is not going to work. You can however just set this up as a manual property in your partial class e.g. on your Library class you could declare:

public LibrarySummary LibrarySummary
{
  get { return UnitOfWork.FindById<LibrarySummary>(Id); }
}

And then set up the reverse of that on LibrarySummary.

Jeremy