ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Core.Data Namespace / JoinType Enumeration
Example Example Version

JoinType Enumeration
Specifies the type of join.
Syntax
Members
MemberDescription
InnerJoin Inner join. Only matched source rows are included.
LeftOuterJoin Left outer join. All source rows are included.
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.JoinType

Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also