public static Relation Projection(Relation3 relation, int row)
{
// resulting Relation
var res = new Relation(relation.ModelId, relation.ProjectId);
var rescollection = res.Collection as ObservableCollection <Tuple <Guid, Guid> >;
// Source Relation
var srcCollection = relation.Collection as ObservableCollection <Tuple <Guid, Guid, Guid> >;
foreach (var item in srcCollection)
{
switch (row)
{
case 1:
rescollection.Add(new Tuple <Guid, Guid>(item.Item2, item.Item3));
break;
case 2:
rescollection.Add(new Tuple <Guid, Guid>(item.Item1, item.Item3));
break;
case 3:
rescollection.Add(new Tuple <Guid, Guid>(item.Item1, item.Item2));
break;
}
}
return(res);
}
// public Relation Projection()
// {
// var res = new Relation(ModelId, ProjectId);
// var collection = res.Collection as ObservableCollection<Tuple<Guid, Guid>>;
//
// foreach (var item in collection)
// {
// collection.Add(new Tuple<Guid, Guid>(item.Item1, item.Item3));
// }
// return res;
// }
public static Relation3 Join(Relation relation1, Relation relation2)
{
var res = new Relation3(relation1.ModelId, relation1.ProjectId);
var collection = res.Collection as ObservableCollection <Tuple <Guid, Guid, Guid> >;
var observableCollection1 = relation1.Collection as ObservableCollection <Tuple <Guid, Guid> >;
if (observableCollection1 == null)
{
return(null);
}
var observableCollection2 = relation2.Collection as ObservableCollection <Tuple <Guid, Guid> >;
if (observableCollection2 == null)
{
return(null);
}
foreach (var item in observableCollection1)
{
foreach (var item2 in observableCollection2)
{
if (item.Item2.Equals(item2.Item1))
{
collection.Add(new Tuple <Guid, Guid, Guid>(item.Item1, item.Item2, item2.Item2));
}
}
}
return(res);
}