ArcGIS Pro 3.3 API Reference Guide
ArcGIS.Core.Data Namespace / JoinDirection Enumeration
Example Example

In This Topic
    JoinDirection Enumeration
    In This Topic
    Specifies the direction of the join.
    Syntax
    Members
    MemberDescription
    Backward The join proceeds from the right table to the left table.
    Forward The join proceeds from the left table to the right table.
    Example
    Joining a file geodatabase feature class to an Oracle database query layer feature class with a virtual relationship class
    public async Task JoiningFileGeodatabaseFeatureClassToOracleQueryLayer()
    {
      await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
      {
        using (Geodatabase geodatabase = new Geodatabase(new FileGeodatabaseConnectionPath(new Uri("C:\\Data\\LocalGovernment.gdb"))))
        using (Database database = new Database(new DatabaseConnectionProperties(EnterpriseDatabaseType.Oracle)
        {
          AuthenticationMode = AuthenticationMode.DBMS,
          Instance = "instance",
          User = "user",
          Password = "password",
          Database = "database"
        }))
    
        using (FeatureClass leftFeatureClass = geodatabase.OpenDataset<FeatureClass>("Hospital"))
        using (Table rightTable = database.OpenTable(database.GetQueryDescription("FacilitySite")))
        {
          Field originPrimaryKey = leftFeatureClass.GetDefinition().GetFields().FirstOrDefault(field => field.Name.Equals("facilityId"));
          Field destinationForeignKey = rightTable.GetDefinition().GetFields().FirstOrDefault(field => field.Name.Equals("hospitalID"));
    
          VirtualRelationshipClassDescription description = new VirtualRelationshipClassDescription(
            originPrimaryKey, destinationForeignKey, RelationshipCardinality.OneToOne);
    
          using (RelationshipClass relationshipClass = leftFeatureClass.RelateTo(rightTable, description))
          {
            JoinDescription joinDescription = new JoinDescription(relationshipClass)
            {
              JoinDirection = JoinDirection.Forward,
              JoinType = JoinType.LeftOuterJoin
            };
    
            Join join = new Join(joinDescription);
    
            using (Table joinedTable = join.GetJoinedTable())
            {
              // Perform operation on joined table.
            }
          }
        }
      });
    }
    Joining two tables from different geodatabases
    public async Task JoinTablesFromDifferentGeodatabases()
    {
      await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
      {
        using (Geodatabase sourceGeodatabase = new Geodatabase(new FileGeodatabaseConnectionPath(new Uri("Path \\ to \\Geodatabase \\ one"))))
        using (Geodatabase destinationGeodatabase = new Geodatabase(new FileGeodatabaseConnectionPath(new Uri("Path \\ to \\Geodatabase \\ two"))))
        using (Table sourceTable = sourceGeodatabase.OpenDataset<Table>("State"))
        using (Table destinationTable = destinationGeodatabase.OpenDataset<Table>("Cities"))
        {
          Field primaryKeyField = sourceTable.GetDefinition().GetFields().FirstOrDefault(field => field.Name.Equals("State.State_Abbreviation"));
          Field foreignKeyField = destinationTable.GetDefinition().GetFields().FirstOrDefault(field => field.Name.Equals("Cities.State"));
    
          VirtualRelationshipClassDescription virtualRelationshipClassDescription = new VirtualRelationshipClassDescription(primaryKeyField, foreignKeyField, RelationshipCardinality.OneToMany);
    
          using (RelationshipClass relationshipClass = sourceTable.RelateTo(destinationTable, virtualRelationshipClassDescription))
          {
            JoinDescription joinDescription = new JoinDescription(relationshipClass)
            {
              JoinDirection = JoinDirection.Forward,
              JoinType = JoinType.InnerJoin,
              TargetFields = sourceTable.GetDefinition().GetFields()
            };
    
            using (Join join = new Join(joinDescription))
            {
              Table joinedTable = join.GetJoinedTable();
    
              //Process the joined table. For example ..
              using (RowCursor cursor = joinedTable.Search())
              {
                while (cursor.MoveNext())
                {
                  using (Row row = cursor.Current)
                  {
                    // Use Row
                  }
                }
              }
            }
          }
        }
      });
    }
    Inheritance Hierarchy

    System.Object
       System.ValueType
          System.Enum
             ArcGIS.Core.Data.JoinDirection

    Requirements

    Target Platforms: Windows 11, Windows 10

    ArcGIS Pro version: 3 or higher.
    See Also