ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Core.Data.Knowledge Namespace / KnowledgeGraphRelationshipType Class
Members Example

In This Topic
    KnowledgeGraphRelationshipType Class
    In This Topic
    Represents a relationship type in the knowledge graph.
    Syntax
    public sealed class KnowledgeGraphRelationshipType : KnowledgeGraphNamedObjectType, System.IDisposable  
    Public NotInheritable Class KnowledgeGraphRelationshipType 
       Inherits KnowledgeGraphNamedObjectType
       Implements System.IDisposable 
    Example
    Check Whether A Graph Type has a Spatial Property
    //Use GetDocumentEntityTypeName(KnowledgeGraphDataModel kg_dm) from
    //the 'Get Whether KG Has a Document Type' snippet to
    //get the documentNameType parameter
    protected bool HasGeometry(KnowledgeGraphNamedObjectType kg_named_obj)
    {
      var props = kg_named_obj.GetProperties();
      return props.Any(prop => prop.FieldType == FieldType.Geometry);
    }
    
    Get KnowledgeGraph Relationship Types
    QueuedTask.Run(() =>
    {
      //Create a connection properties
      var kg_props =
          new KnowledgeGraphConnectionProperties(new Uri(url));
      using (var kg = new KnowledgeGraph(kg_props))
      {
        //Get the KnowledgeGraph Data Model
        using (var kg_dm = kg.GetDataModel())
        {
          var dict_types = kg_dm.GetRelationshipTypes();
    
          foreach (var kvp in dict_types)
          {
            var rel_type = kvp.Value;
            var role = rel_type.GetRole();
            //note "name" will be the same name as the corresponding
            //feature class or table in the KG's relational gdb model
            var name = rel_type.GetName();
            //etc.
            //Get relationship end points
            var end_points = rel_type.GetEndPoints();
            foreach (var end_point in end_points)
            {
              System.Diagnostics.Debug.WriteLine(
                $"Origin: '{end_point.GetOriginEntityTypeName()}', " +
                $"Destination: '{end_point.GetDestinationEntityTypeName()}'");
            }
          }
    
        }
      }
    });
    
    Create a new Relationship and New Entities 1
    var create_rel1 = await QueuedTask.Run(() =>
    {
      //This example uses a chained edit operation
      var edit_op = new EditOperation()
      {
        Name = "Create entities and a relationship",
        SelectNewFeatures = true
      };
    
      //We are just going to use the GDB objects in this one but
      //we could equally use feature layers/standalone tables
    
      //using Feature Class/Tables (works within Investigation or map)
      var org_fc = kg.OpenDataset<FeatureClass>("Organization");
      var person_tbl = kg.OpenDataset<Table>("Person");
      //Relationship table
      var emp_tbl = kg.OpenDataset<Table>("HasEmployee");
    
      var attribs = new Dictionary<string, object>();
    
      //New Organization
      attribs["Name"] = "Acme Ltd.";
      attribs["Description"] = "Specializes in household items";
      attribs["SHAPE"] = org_location;
    
      //Add it to the operation - we need the rowtoken
      var rowtoken = edit_op.Create(org_fc, attribs);
    
      attribs.Clear();//we are going to re-use the dictionary
    
      //New Person
      attribs["Name"] = "Bob";
      attribs["Age"] = "41";
      attribs["Skills"] = "Plumbing, Framing, Flooring";
    
      //Add it to the operation
      var rowtoken2 = edit_op.Create(person_tbl, attribs);
    
      attribs.Clear();
    
      //At this point we must execute the create of the entities
      if (edit_op.Execute())
      {
        //if we are here, the create of the entities was successful
    
        //Next, "chain" a second create for the relationship - this ensures that
        //Both creates (entities _and_ relation) will be -undone- together if needed
        //....in other words they will behave as if they are a -single- transaction
        var edit_op_rel = edit_op.CreateChainedOperation();
    
        //we need the names of the origin and destination relation properties
        var kg_prop_info = kg.GetPropertyNameInfo();
        //use the row tokens we held on to from the entity creates
        attribs[kg_prop_info.OriginIDPropertyName] = rowtoken.GlobalID;
        attribs[kg_prop_info.DestinationIDPropertyName] = rowtoken2.GlobalID;
    
        //Add any extra attribute information for the relation as needed
        attribs["StartDate"] = new DateTimeOffset(DateTime.Now);
    
        //Do the create of the relate
        edit_op_rel.Create(emp_tbl, attribs);
        return edit_op_rel.Execute();
      }
      return false;//Create of entities failed
    });
    
    Create a new Relationship and New Entities 2
    var createRel = await QueuedTask.Run(() =>
    {
      //This example uses a KnowledgeGraphRelationshipDescription
      var edit_op = new EditOperation()
      {
        Name = "Create entities and a relationship using a KG relate desc",
        SelectNewFeatures = true
      };
    
      //We are just going to use mapmembers in this example
      //we could equally use feature classes/tables
      var kg_layer = mv.Map.GetLayersAsFlattenedList()?
                    .OfType<ArcGIS.Desktop.Mapping.KnowledgeGraphLayer>().First();
      //From the KG Layer get the relevant child feature layer(s) and/or standalone
      //table(s)
      var org_fl = kg_layer.GetLayersAsFlattenedList().OfType<FeatureLayer>()
                      .First(child_layer => child_layer.Name == "Organization");
    
      var person_stbl = kg_layer.GetStandaloneTablesAsFlattenedList()
                      .First(child_layer => child_layer.Name == "Person");
    
      var rel_stbl = kg_layer.GetStandaloneTablesAsFlattenedList()
                      .First(child_layer => child_layer.Name == "HasEmployee");
    
      var attribs = new Dictionary<string, object>();
    
      //New Organization
      attribs["Name"] = "Acme Ltd.";
      attribs["Description"] = "Specializes in household items";
      attribs["SHAPE"] = org_location;
    
      //Add it to the operation - we need the rowtoken
      var rowtoken_org = edit_op.Create(org_fl, attribs);
    
      attribs.Clear();//we are going to re-use the dictionary
    
      //New Person
      attribs["Name"] = "Bob";
      attribs["Age"] = "41";
      attribs["Skills"] = "Plumbing, Framing, Flooring";
    
      //Add it to the operation
      var rowtoken_person = edit_op.Create(person_stbl, attribs);
    
      attribs.Clear();
    
      //Create the new relationship using a KnowledgeGraphRelationshipDescription
      //Row handles act as the placeholders for the TO BE created new entities that will
      //be related
      var src_row_handle = new RowHandle(rowtoken_org);
      var dest_row_handle = new RowHandle(rowtoken_person);
    
      //Add any extra attribute information for the relation as needed
      attribs["StartDate"] = new DateTimeOffset(DateTime.Now);
    
      var rel_desc = new KnowledgeGraphRelationshipDescription(
                                  src_row_handle, dest_row_handle, attribs);
    
      //Add the relate description to the edit operation
      edit_op.Create(rel_stbl, rel_desc);
    
      //Execute the create of the entities and relationship
      return edit_op.Execute();
    });
    
    Create a Document Record
    internal static string GetDocumentTypeName(KnowledgeGraphDataModel kg_dm)
    {
      var entity_types = kg_dm.GetEntityTypes();
      foreach (var entity_type in entity_types)
      {
        var role = entity_type.Value.GetRole();
        if (role == KnowledgeGraphNamedObjectTypeRole.Document)
          return entity_type.Value.GetName();
      }
      return "";
    }
    
    internal static string GetHasDocumentTypeName(KnowledgeGraphDataModel kg_dm)
    {
      var rel_types = kg_dm.GetRelationshipTypes();
      foreach (var rel_type in rel_types)
      {
        var role = rel_type.Value.GetRole();
        if (role == KnowledgeGraphNamedObjectTypeRole.Document)
          return rel_type.Value.GetName();
      }
      return "";
    }
    
    internal async void AddDocumentRecord()
    {
    
      await QueuedTask.Run(() =>
      {
        using (var kg = GetKnowledgeGraph())
        {
          var edit_op = new EditOperation()
          {
            Name = "Create Document Example",
            SelectNewFeatures = true
          };
    
          var doc_entity_name = GetDocumentTypeName(kg.GetDataModel());
          if (string.IsNullOrEmpty(doc_entity_name))
            return false;
          var hasdoc_rel_name = GetHasDocumentTypeName(kg.GetDataModel());
          if (string.IsNullOrEmpty(hasdoc_rel_name))
            return false;
    
          //Document can also be FeatureClass
          var doc_tbl = kg.OpenDataset<Table>(doc_entity_name);
          var doc_rel_tbl = kg.OpenDataset<Table>(hasdoc_rel_name);
    
          //This is the document to be added...file, image, resource, etc.
          var url = @"E:\Data\Temp\HelloWorld.txt";
          var text = System.IO.File.ReadAllText(url);
    
          //Set document properties
          var attribs = new Dictionary<string, object>();
          attribs["contentType"] = @"text/plain";
          attribs["name"] = System.IO.Path.GetFileName(url);
          attribs["url"] = url;
          //Add geometry if relevant
          //attribs["Shape"] = doc_location;
    
          //optional
          attribs["fileExtension"] = System.IO.Path.GetExtension(url);
          attribs["text"] = System.IO.File.ReadAllText(url);
    
          //optional and arbitrary - your choice
          attribs["title"] = System.IO.Path.GetFileNameWithoutExtension(url);
          attribs["keywords"] = @"text,file,example";
          attribs["metadata"] = "";
    
          //Specify any additional custom attributes added to the document
          //schema by the user as needed....
          //attribs["custom_attrib"] = "Foo";
          //attribs["custom_attrib2"] = "Bar";
    
          //Get the entity whose document this is...
          var org_fc = kg.OpenDataset<FeatureClass>("Organization");
          var qf = new QueryFilter()
          {
            WhereClause = "name = 'Acme'",
            SubFields = "*"
          };
          var origin_org_id = Guid.Empty;
          using (var rc = org_fc.Search(qf))
          {
            if (!rc.MoveNext())
              return false;
            origin_org_id = rc.Current.GetGlobalID();//For the relate
          }
    
          //Create the document row/feature
          var rowtoken = edit_op.Create(doc_tbl, attribs);
          if (edit_op.Execute())
          {
            //Create the relationship row
            attribs.Clear();
            //we need the names of the origin and destination relation properties
            var kg_prop_info = kg.GetPropertyNameInfo();
            //Specify the origin entity (i.e. the document 'owner') and
            //the document being related to (i.e. the document 'itself')
            attribs[kg_prop_info.OriginIDPropertyName] = origin_org_id;//entity
            attribs[kg_prop_info.DestinationIDPropertyName] = rowtoken.GlobalID;//document
    
            //Specify any custom attributes added to the has document
            //schema by the user as needed....
            //attribs["custom_attrib"] = "Foo";
            //attribs["custom_attrib2"] = "Bar";
    
            //"Chain" a second create for the relationship - this ensures that
            //Both creates (doc _and_ "has doc" relation) will be -undone- together if needed
            //....in other words they will behave as if they are a -single- transaction
            var edit_op_rel = edit_op.CreateChainedOperation();
            edit_op_rel.Create(doc_rel_tbl, attribs);
            return edit_op_rel.Execute();
          }
        }
        return false;
      });
    }
    
    Delete an Entity record
    await QueuedTask.Run(() =>
    {
    
      var edit_op = new EditOperation()
      {
        Name = "Delete an Entity record"
      };
    
      //We are  going to use mapmembers in this example
      //we could equally use feature classes/tables
      var kg_layer = mv.Map.GetLayersAsFlattenedList()?
                    .OfType<ArcGIS.Desktop.Mapping.KnowledgeGraphLayer>().First();
      //Entity
      var org_fl = kg_layer.GetLayersAsFlattenedList().OfType<FeatureLayer>()
                      .First(child_layer => child_layer.Name == "Organization");
    
      //Get the entity feature(s) to delete
      long org_oid = -1;
      var qf = new QueryFilter()
      {
        WhereClause = "name = 'Acme'",
        SubFields = "*"
      };
      using (var rc = org_fl.Search(qf))
      {
        if (!rc.MoveNext())
          return;//nothing to delete
        org_oid = rc.Current.GetObjectID();
      } 
    
      edit_op.Delete(org_fl, org_oid);
      edit_op.Execute();//Do the delete
    });
    Delete a Relationship record 1
    await QueuedTask.Run(() =>
    {
    
      var edit_op = new EditOperation()
      {
        Name = "Delete a Relationship record"
      };
    
      //We are  going to use mapmembers in this example
      //we could equally use feature classes/tables
      var kg_layer = mv.Map.GetLayersAsFlattenedList()?
                    .OfType<ArcGIS.Desktop.Mapping.KnowledgeGraphLayer>().First();
      //Relationship
      var rel_stbl = kg_layer.GetStandaloneTablesAsFlattenedList()
                      .First(child_layer => child_layer.Name == "HasEmployee");
    
      //Get the relation row to delete
      long rel_oid = -1;
      using (var rc = rel_stbl.Search())
      {
        if (!rc.MoveNext())
          return;
        //arbitrarily, in this example, get the first row
        rel_oid = rc.Current.GetObjectID();
      }
    
      edit_op.Delete(rel_stbl, rel_oid);
      edit_op.Execute();//Do the delete
    });
    Delete a Relationship record 2
    await QueuedTask.Run(() =>
    {
    
      var edit_op = new EditOperation()
      {
        Name = "Delete a Relationship record"
      };
    
      //We are  going to use mapmembers in this example
      //we could equally use feature classes/tables
      var kg_layer = mv.Map.GetLayersAsFlattenedList()?
                    .OfType<ArcGIS.Desktop.Mapping.KnowledgeGraphLayer>().First();
    
      //entities
      var entityOrg = kg_layer.GetStandaloneTablesAsFlattenedList()
                      .First(child_layer => child_layer.Name == "Organization");
      var entityPerson = kg_layer.GetStandaloneTablesAsFlattenedList()
                      .First(child_layer => child_layer.Name == "Person");
    
      //Relationship
      var rel_stbl = kg_layer.GetStandaloneTablesAsFlattenedList()
                      .First(child_layer => child_layer.Name == "HasEmployee");
    
      // get the origin, destination records
      Guid guidOrigin = Guid.Empty;
      Guid guidDestination = Guid.Empty;
      using (var rc = entityOrg.Search())
      {
        if (rc.MoveNext())
          //Use the KnowledgeGraphPropertyInfo to avoid hardcoding...
          guidOrigin = rc.Current.GetGlobalID();
      }
      using (var rc = entityPerson.Search())
      {
        if (rc.MoveNext())
          //Use the KnowledgeGraphPropertyInfo to avoid hardcoding...
          guidDestination = rc.Current.GetGlobalID();
      }
    
      var rd = new KnowledgeGraphRelationshipDescription(guidOrigin, guidDestination);
      edit_op.Delete(rel_stbl, rd);
      edit_op.Execute();//Do the delete
    });
    Inheritance Hierarchy

    System.Object
       ArcGIS.Core.CoreObjectsBase
          ArcGIS.Core.Data.Knowledge.KnowledgeGraphNamedObjectType
             ArcGIS.Core.Data.Knowledge.KnowledgeGraphRelationshipType

    Requirements

    Target Platforms: Windows 11, Windows 10

    ArcGIS Pro version: 3.2 or higher.
    See Also