ArcGIS Pro 3.2 API Reference Guide
ArcGIS.Core.Data Namespace / JoinDescription Class
Members Example

In This Topic
    JoinDescription Class
    In This Topic
    Represents a mechanism to create a Join object.
    Object Model
    JoinDescription ClassQueryFilter ClassRelationshipClass ClassSelection Class
    Syntax
    public sealed class JoinDescription 
    Public NotInheritable Class JoinDescription 
    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
       ArcGIS.Core.Data.JoinDescription

    Requirements

    Target Platforms: Windows 11, Windows 10

    ArcGIS Pro version: 3 or higher.
    See Also