support for importing-exporting CityObjectRelation

.idea/gradle.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>

.idea/misc.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ExternalStorageConfigurationManager" enabled="true" />
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" project-jdk-name="liberica-17" project-jdk-type="JavaSDK" />
+  <component name="FrameworkDetectionExcludesConfiguration">
+    <file type="web" url="file://$PROJECT_DIR$" />
+    <file type="web" url="file://$PROJECT_DIR$/../energy-ade-3-citygml4j" />
+  </component>
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="liberica-17" project-jdk-type="JavaSDK" />
 </project>
\ No newline at end of file

.idea/vcs.xml

@@ -2,5 +2,6 @@
 <project version="4">
   <component name="VcsDirectoryMappings">
     <mapping directory="" vcs="Git" />
+    <mapping directory="$PROJECT_DIR$/../energy-ade-3-citygml4j" vcs="Git" />
   </component>
 </project>
\ No newline at end of file

README.md

@@ -12,7 +12,7 @@ Currently, there are _no plans to migrate_ the Energy ADE 3 importer-exporter AP
 
 The following modules are supported at the moment:
 
--  Core (AbstractBuilding, RefurbishmentMeasures, WeatherData)
+-  Core (AbstractBuilding, RefurbishmentMeasures, WeatherData, CityObjectRelation)
 -  Resource
 -  UrbanFunctionArea
 -  WeatherStation

build.gradle

@@ -8,8 +8,8 @@ plugins {
 }
 
 group = 'de.stuttgart.hft'
-version = 'beta7-0.3'
-description 'Energy ADE 3 (beta 7) extension for the 3DCityDB - release 0.3'
+version = 'beta7-0.4'
+description 'Energy ADE 3 (beta 7) extension for the 3DCityDB - release 0.4'
 
 repositories {
     maven {

resources/database/3dcitydb/postgreSQL/DROP_ADE_DB.sql

--- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
--- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
---
--- CityGML Energy ADE 3.0 (beta 7)
---
--- Last update: 2025-10-14
---
--- This DDL script uninstalls the 3DCityDB schema for the Energy ADE. It must be run
--- from within the ADE Manager plugin of the 3DCityDB Importer/Exporter.
---
--- This script was first automatically generated using the 3DCityDB ADE Manager
--- and successively edited and restructured by:
---
--- Dr. Giorgio Agugiaro
--- 3D Geoinformation group
--- Delft University of Technology
--- The Netherlands
---
--- https://3d.bk.tudelft.nl/gagugiaro/
---
--- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
--- ******************************* DROP_ADE_DB.SQL execution START ************************ 
--- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-
--- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
--- *********************************** Drop foreign keys ********************************** 
--- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
-ALTER TABLE ng3_address_to_building_unit DROP CONSTRAINT ng3_addr_to_bdgu_fk1;
-ALTER TABLE ng3_address_to_building_unit DROP CONSTRAINT ng3_addr_to_bdgu_fk2;
-ALTER TABLE ng3_building DROP CONSTRAINT ng3_bdg_fk;
-ALTER TABLE ng3_building_partition DROP CONSTRAINT ng3_bdgp_bdg_fk;
-ALTER TABLE ng3_building_partition DROP CONSTRAINT ng3_bdgp_fk;
-ALTER TABLE ng3_building_partition DROP CONSTRAINT ng3_bdgp_lod1_fk;
-ALTER TABLE ng3_building_partition DROP CONSTRAINT ng3_bdgp_lod2_fk;
-ALTER TABLE ng3_building_partition DROP CONSTRAINT ng3_bdgp_lod3_fk;
-ALTER TABLE ng3_building_partition DROP CONSTRAINT ng3_bdgp_oc_fk;
-ALTER TABLE ng3_building_partition DROP CONSTRAINT ng3_bdgp_sched_fk1;
-ALTER TABLE ng3_building_partition DROP CONSTRAINT ng3_bdgp_sched_fk2;
-ALTER TABLE ng3_building_partition DROP CONSTRAINT ng3_bdgp_sched_fk3;
-ALTER TABLE ng3_building_partition DROP CONSTRAINT ng3_bdgp_tz_fk;
-ALTER TABLE ng3_building_partition DROP CONSTRAINT ng3_bdgp_uz_fk;
-ALTER TABLE ng3_cityobject DROP CONSTRAINT ng3_cto_fk;
-ALTER TABLE ng3_cityobject DROP CONSTRAINT ng3_cto_lcns_fk;
-ALTER TABLE ng3_ctyobj_relation DROP CONSTRAINT ng3_cto_rel_fk1;
-ALTER TABLE ng3_ctyobj_relation DROP CONSTRAINT ng3_cto_rel_fk2;
-ALTER TABLE ng3_device DROP CONSTRAINT ng3_dev_fk;
-ALTER TABLE ng3_device DROP CONSTRAINT ng3_dev_ng3_cto_fk;
-ALTER TABLE ng3_device DROP CONSTRAINT ng3_dev_oc_fk;
-ALTER TABLE ng3_device DROP CONSTRAINT ng3_dev_opt_fk;
-ALTER TABLE ng3_device_operation DROP CONSTRAINT ng3_dev_opr_fk;
-ALTER TABLE ng3_device_operation DROP CONSTRAINT ng3_dev_opr_dev_fk;
-ALTER TABLE ng3_device_operation DROP CONSTRAINT ng3_dev_opr_sched_fk;
-ALTER TABLE ng3_energy_perf_cert DROP CONSTRAINT ng3_epc_fk;
-ALTER TABLE ng3_energy_perf_cert DROP CONSTRAINT ng3_epc_bdg_fk;
-ALTER TABLE ng3_energy_perf_cert DROP CONSTRAINT ng3_epc_bdg_part_fk;
-ALTER TABLE ng3_layer DROP CONSTRAINT ng3_lyr_fk;
-ALTER TABLE ng3_layer DROP CONSTRAINT ng3_lyr_lcns_fk;
-ALTER TABLE ng3_layer DROP CONSTRAINT ng3_lyr_mat_fk;
-ALTER TABLE ng3_layered_construction DROP CONSTRAINT ng3_lcns_fk;
-ALTER TABLE ng3_layered_construction DROP CONSTRAINT ng3_lcns_lcns_fk;
-ALTER TABLE ng3_layered_construction DROP CONSTRAINT ng3_lcns_oc_fk;
-ALTER TABLE ng3_layered_construction DROP CONSTRAINT ng3_lcns_lib_fk;
-ALTER TABLE ng3_library DROP CONSTRAINT ng3_lib_fk;
-ALTER TABLE ng3_library DROP CONSTRAINT ng3_lib_oc_fk;
-ALTER TABLE ng3_material DROP CONSTRAINT ng3_mat_fk;
-ALTER TABLE ng3_material DROP CONSTRAINT ng3_mat_lib_fk;
-ALTER TABLE ng3_occupants DROP CONSTRAINT ng3_occ_fk;
-ALTER TABLE ng3_occupants DROP CONSTRAINT ng3_occ_ng3_bdgp_fk;
-ALTER TABLE ng3_occupants DROP CONSTRAINT ng3_occ_sched_fk;
-ALTER TABLE ng3_opening DROP CONSTRAINT ng3_opn_fk;
-ALTER TABLE ng3_optical_property DROP CONSTRAINT ng3_optpty_lcns_fk;
-ALTER TABLE ng3_optical_property DROP CONSTRAINT ng3_optpty_oc_fk; 
-ALTER TABLE ng3_qualified_attribute DROP CONSTRAINT ng3_qatt_oc_fk; 
-ALTER TABLE ng3_qualified_attribute DROP CONSTRAINT ng3_qatt_bdg_fk;
-ALTER TABLE ng3_qualified_attribute DROP CONSTRAINT ng3_qatt_bdg_part_fk;
-ALTER TABLE ng3_refurbishment_measure DROP CONSTRAINT ng3_refurb_fk;
-ALTER TABLE ng3_refurbishment_measure DROP CONSTRAINT ng3_refurb_bdg_fk;
-ALTER TABLE ng3_refurbishment_measure DROP CONSTRAINT ng3_refurb_bdg_part_fk;
-ALTER TABLE ng3_resource DROP CONSTRAINT ng3_res_fk;
-ALTER TABLE ng3_resource DROP CONSTRAINT ng3_res_oc_fk;
-ALTER TABLE ng3_resource DROP CONSTRAINT ng3_res_ts_fk;
-ALTER TABLE ng3_resource DROP CONSTRAINT ng3_res_cto_fk;
-ALTER TABLE ng3_schedule DROP CONSTRAINT ng3_sched_fk;
-ALTER TABLE ng3_schedule DROP CONSTRAINT ng3_sched_oc_fk;
-ALTER TABLE ng3_schedule DROP CONSTRAINT ng3_sched_ts_fk;
-ALTER TABLE ng3_schedule DROP CONSTRAINT ng3_sched_lib_fk;
-ALTER TABLE ng3_schedule_component DROP CONSTRAINT ng3_sched_comp_fk;
-ALTER TABLE ng3_schedule_component DROP CONSTRAINT ng3_sched_comp_sched_fk1;
-ALTER TABLE ng3_schedule_component DROP CONSTRAINT ng3_sched_comp_sched_fk2;
-ALTER TABLE ng3_solar_collector DROP CONSTRAINT ng3_sol_coll_fk;
-ALTER TABLE ng3_solar_collector DROP CONSTRAINT ng3_sol_coll_oc_fk;
-ALTER TABLE ng3_solar_collector DROP CONSTRAINT ng3_sol_coll_lod2_fk;
-ALTER TABLE ng3_solar_collector DROP CONSTRAINT ng3_sol_coll_lod3_fk;
-ALTER TABLE ng3_storage_device DROP CONSTRAINT ng3_sto_dev_fk;
-ALTER TABLE ng3_storage_device DROP CONSTRAINT ng3_sto_dev_oc_fk;
-ALTER TABLE ng3_suitability DROP CONSTRAINT ng3_suit_cto_fk;
-ALTER TABLE ng3_suitability DROP CONSTRAINT ng3_suit_sched_fk;
-ALTER TABLE ng3_them_surf_to_thermal_zone DROP CONSTRAINT ng3_thm_surf_to_tz_fk1;
-ALTER TABLE ng3_them_surf_to_thermal_zone DROP CONSTRAINT ng3_thm_surf_to_tz_fk2;
-ALTER TABLE ng3_thematic_surface DROP CONSTRAINT ng3_them_surf_fk;
-ALTER TABLE ng3_time_series DROP CONSTRAINT ng3_ts_fk;
-ALTER TABLE ng3_time_series DROP CONSTRAINT ng3_ts_oc_fk;
-ALTER TABLE ng3_urban_function_area DROP CONSTRAINT ng3_ufa_fk;
-ALTER TABLE ng3_utl_ntw_connection DROP CONSTRAINT ng3_utl_ntw_con_cto_fk;
-ALTER TABLE ng3_utl_ntw_connection DROP CONSTRAINT ng3_utl_ntw_con_fk;
-ALTER TABLE ng3_weather_data DROP CONSTRAINT ng3_wth_data_fk;
-ALTER TABLE ng3_weather_data DROP CONSTRAINT ng3_wth_data_ng3_cto_fk;
-ALTER TABLE ng3_weather_data DROP CONSTRAINT ng3_wth_data_ts_fk;
-
--- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
--- *********************************** Drop tables *************************************** 
--- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
-DROP TABLE ng3_address_to_building_unit CASCADE;
-DROP TABLE ng3_building CASCADE;
-DROP TABLE ng3_building_partition CASCADE;
-DROP TABLE ng3_cityobject CASCADE;
-DROP TABLE ng3_ctyobj_relation CASCADE;
-DROP TABLE ng3_device CASCADE;
-DROP TABLE ng3_device_operation CASCADE;
-DROP TABLE ng3_energy_perf_cert CASCADE;
-DROP TABLE ng3_layer CASCADE;
-DROP TABLE ng3_layered_construction CASCADE;
-DROP TABLE ng3_library CASCADE;
-DROP TABLE ng3_material CASCADE;
-DROP TABLE ng3_occupants CASCADE;
-DROP TABLE ng3_opening CASCADE;
-DROP TABLE ng3_optical_property CASCADE;
-DROP TABLE ng3_qualified_attribute CASCADE;
-DROP TABLE ng3_refurbishment_measure CASCADE;
-DROP TABLE ng3_resource CASCADE;
-DROP TABLE ng3_schedule CASCADE;
-DROP TABLE ng3_schedule_component CASCADE;
-DROP TABLE ng3_solar_collector CASCADE;
-DROP TABLE ng3_storage_device CASCADE;
-DROP TABLE ng3_suitability CASCADE;
-DROP TABLE ng3_them_surf_to_thermal_zone CASCADE;
-DROP TABLE ng3_thematic_surface CASCADE;
-DROP TABLE ng3_time_series CASCADE;
-DROP TABLE ng3_urban_function_area CASCADE;
-DROP TABLE ng3_utl_ntw_connection CASCADE;
-DROP TABLE ng3_weather_data CASCADE;
-
--- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
--- *********************************** Drop Sequences ************************************* 
--- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
-DROP SEQUENCE ng3_ctyobj_relation_seq;
-DROP SEQUENCE ng3_optical_property_seq;
-DROP SEQUENCE ng3_qualified_attribute_seq;
-DROP SEQUENCE ng3_suitability_seq;
\ No newline at end of file

src/main/java/de/stuttgart/hft/ade/energy3/exporter/CityObjectPropertiesExporter.java

@@ -66,6 +66,12 @@ public class CityObjectPropertiesExporter implements ADEExporter {
                     }
                 }
 
+                if (projectionFilter.containsProperty("relatedTo", module)) {
+                    for (CityObjectRelationProperty property : manager.getExporter(CityObjectRelationExporter.class).doExport(objectId)) {
+                        cityObject.addGenericApplicationPropertyOfCityObject(property);
+                    }
+                }
+
                 if (pointObj != null) {
                     GeometryObject pointObject = helper.getDatabaseAdapter().getGeometryConverter().getPoint(pointObj);
                     if (pointObject != null) {

src/main/java/de/stuttgart/hft/ade/energy3/exporter/CityObjectRelationExporter.java

+package de.stuttgart.hft.ade.energy3.exporter;
+
+import de.stuttgart.hft.ade.energy3.schema.ADETable;
+import org.citydb.core.ade.exporter.ADEExporter;
+import org.citydb.core.ade.exporter.CityGMLExportHelper;
+import org.citydb.core.operation.exporter.CityGMLExportException;
+import org.citygml4j.ade.energy3.model.core.CityObjectRelation;
+import org.citygml4j.ade.energy3.model.core.CityObjectRelationProperty;
+import org.citygml4j.ade.energy3.model.core.RelatedToProperty;
+import org.citygml4j.model.gml.basicTypes.Code;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.Collection;
+
+public class CityObjectRelationExporter implements ADEExporter {
+
+    private final PreparedStatement ps;
+    private final CityGMLExportHelper helper;
+
+    public CityObjectRelationExporter(Connection connection, CityGMLExportHelper helper, ExportManager manager) throws CityGMLExportException, SQLException {
+        this.helper = helper;
+
+        // Query ng3_ctyobj_relation joined to cityobject to get the target GML ID
+        ps = connection.prepareStatement(
+                "SELECT r.relation_type, r.relation_type_codespace, co.gmlid " +
+                        "FROM " + helper.getTableNameWithSchema(manager.getSchemaMapper().getTableName(ADETable.CTYOBJ_RELATION)) + " r " +
+                        "JOIN cityobject co ON co.id = r.cityobject_id " +
+                        "WHERE r.ng3_cityobject_id = ?"
+        );
+    }
+
+    public Collection<CityObjectRelationProperty> doExport(long ng3CityObjectId) throws CityGMLExportException, SQLException {
+        ps.setLong(1, ng3CityObjectId);
+
+        Collection<CityObjectRelationProperty> result = new ArrayList<>();
+        try (ResultSet rs = ps.executeQuery()) {
+            while (rs.next()) {
+                String relationType         = rs.getString(1);
+                String relationTypeCodespace = rs.getString(2);
+                String targetGmlId          = rs.getString(3);
+
+                CityObjectRelation relation = new CityObjectRelation();
+
+                // Set relationType
+                if (relationType != null) {
+                    Code code = new Code(relationType);
+                    if (relationTypeCodespace != null)
+                        code.setCodeSpace(relationTypeCodespace);
+                    relation.setRelationType(code);
+                }
+
+                // Set relatedTo as xlink:href pointing to the target city object GML ID
+                if (targetGmlId != null) {
+                    RelatedToProperty relatedTo = new RelatedToProperty();
+                    relatedTo.setHref("#" + targetGmlId);
+                    relation.setRelatedTo(relatedTo);
+                }
+
+                result.add(new CityObjectRelationProperty(relation));
+            }
+        }
+        return result;
+    }
+
+    @Override
+    public void close() throws CityGMLExportException, SQLException {
+        ps.close();
+    }
+}
\ No newline at end of file

src/main/java/de/stuttgart/hft/ade/energy3/exporter/ExportManager.java

@@ -68,6 +68,8 @@ public class ExportManager implements ADEExportManager {
             getExporter(ResourceExporter.class).doExport(parentId);
         else if (adeHookTable.equals(schemaMapper.getTableName(ADETable.BUILDING)) && parent instanceof AbstractBuilding)
             getExporter(BuildingPropertiesExporter.class).doExport((AbstractBuilding) parent, parentId, parentType, projectionFilter);
+        else if (adeHookTable.equals(schemaMapper.getTableName(ADETable.CTYOBJ_RELATION)) && parent instanceof AbstractCityObject)
+            getExporter(CityObjectRelationExporter.class).doExport(parentId);
     }
 
     @Override
@@ -106,6 +108,8 @@ public class ExportManager implements ADEExportManager {
                 exporter = new AbstractQualifiedAttributeExporter(connection, helper, this);
             else if (type == RefurbishmentMeasureExporter.class)
                 exporter = new RefurbishmentMeasureExporter(connection, helper, this);
+            else if (type == CityObjectRelationExporter.class)
+                exporter = new CityObjectRelationExporter(connection, helper, this);
             if (exporter == null)
                 throw new SQLException("Failed to build ADE exporter of type " + type.getName() + ".");
 

src/main/java/de/stuttgart/hft/ade/energy3/exporter/ResourceExporter.java

@@ -48,7 +48,7 @@ public class ResourceExporter implements ADEExporter {
                 }
 
                 ObjectType objectType = helper.getObjectType(objectClassId);
-                ProjectionFilter projectionFilter = helper.getProjectionFilter(objectType);
+                ProjectionFilter projectionFilter = (objectType != null) ? helper.getProjectionFilter(objectType) : null;
 
                 // Set AbstractResource properties
                 String statusValue = rs.getString(7);

src/main/java/de/stuttgart/hft/ade/energy3/importer/CityObjectPropertiesImporter.java

@@ -13,6 +13,7 @@ import org.citygml4j.ade.energy3.model.core.*;
 import org.citygml4j.ade.energy3.model.supportingClasses.*;
 import org.citygml4j.model.citygml.core.AbstractCityObject;
 
+
 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
@@ -96,8 +97,41 @@ public class CityObjectPropertiesImporter implements ADEImporter {
                 }
             }
         }
+
+        if (properties.contains(CityObjectRelationProperty.class)) {
+            for (CityObjectRelationProperty propertyElement : properties.getAll(CityObjectRelationProperty.class)) {
+                CityObjectRelation relation = propertyElement.getObject();
+                if (relation != null && relation.isSetRelatedTo()) {
+                    RelatedToProperty relatedTo = relation.getRelatedTo();
+                    if (relatedTo.isSetHref()) {
+                        // Strip leading # from href to get the GML ID
+                        String targetGmlId = relatedTo.getHref();
+                        if (targetGmlId.startsWith("#"))
+                            targetGmlId = targetGmlId.substring(1);
+                        // Look up target city object ID by GML ID
+                        long targetId = resolveCityObjectId(targetGmlId);
+                        if (targetId > 0)
+                            manager.getImporter(CityObjectRelationImporter.class)
+                                    .doImport(relation, parentId, targetId);
+                    }
+                }
+            }
+        }
     }
 
+    private long resolveCityObjectId(String gmlId) throws SQLException {
+        try (java.sql.PreparedStatement stmt = connection.prepareStatement(
+                "SELECT id FROM cityobject WHERE gmlid = ?")) {
+            stmt.setString(1, gmlId);
+            try (java.sql.ResultSet rs = stmt.executeQuery()) {
+                if (rs.next())
+                    return rs.getLong(1);
+            }
+        }
+        return 0;
+    }
+
+
     @Override
     public void executeBatch() throws CityGMLImportException, SQLException {
         if (batchCounter > 0) {

src/main/java/de/stuttgart/hft/ade/energy3/importer/CityObjectRelationImporter.java

@@ -6,7 +6,6 @@ import org.citydb.core.ade.importer.CityGMLImportHelper;
 import org.citydb.core.ade.importer.ForeignKeys;
 import org.citydb.core.database.schema.mapping.AbstractObjectType;
 import org.citydb.core.operation.importer.CityGMLImportException;
-import org.citydb.core.operation.importer.util.GeometryConverter;
 import org.citygml4j.ade.energy3.model.core.CityObjectRelation;
 
 import java.sql.Connection;
@@ -17,40 +16,37 @@ public class CityObjectRelationImporter implements ADEImporter {
 
     private final Connection connection;
     private final CityGMLImportHelper helper;
+    private final ImportManager manager;
 
-    private GeometryConverter geometryConverter;
     private PreparedStatement ps;
     private int batchCounter;
 
     public CityObjectRelationImporter(Connection connection, CityGMLImportHelper helper, ImportManager manager) throws CityGMLImportException, SQLException {
         this.connection = connection;
         this.helper = helper;
+        this.manager = manager;
 
         ps = connection.prepareStatement("INSERT INTO " +
-                helper.getTableNameWithSchema(manager.getSchemaMapper().getTableName(ADETable.UTL_NTW_CONNECTION)) + " " +
-                "(id, ng2_cityobject_id, cityobject_id, relation_type, relation_type_codespace) " +
-                "VALUES (?, ?, ?, ?, ?)");
-
-        geometryConverter = helper.getGeometryConverter();
-
+                helper.getTableNameWithSchema(manager.getSchemaMapper().getTableName(ADETable.CTYOBJ_RELATION)) + " " +
+                "(id, ng3_cityobject_id, cityobject_id, relation_type, relation_type_codespace) " +
+                "VALUES (nextval('" + manager.getSchemaMapper().getSequenceName(de.stuttgart.hft.ade.energy3.schema.ADESequence.CTYOBJ_RELATION_SEQ) + "'), ?, ?, ?, ?)");
     }
 
-    public void doImport(CityObjectRelation cityObjectRelation, long objectId, AbstractObjectType<?> objectType, ForeignKeys foreignKeys) throws CityGMLImportException, SQLException {
-        ps.setLong(1, objectId);
+    public void doImport(CityObjectRelation cityObjectRelation, long ng3CityObjectId, long targetCityObjectId) throws CityGMLImportException, SQLException {
+        ps.setLong(1, ng3CityObjectId);
+        ps.setLong(2, targetCityObjectId);
 
         if (cityObjectRelation.isSetRelation()) {
-            ps.setString(4, cityObjectRelation.getRelationType().getValue());
-            ps.setString(5, cityObjectRelation.getRelationType().getCodeSpace());
+            ps.setString(3, cityObjectRelation.getRelationType().getValue());
+            ps.setString(4, cityObjectRelation.getRelationType().getCodeSpace());
+        } else {
+            ps.setNull(3, java.sql.Types.VARCHAR);
+            ps.setNull(4, java.sql.Types.VARCHAR);
         }
 
-
-        //set correctly
-        ps.setLong(2, objectType.getObjectClassId());
-        ps.setLong(3, objectType.getObjectClassId());
-
         ps.addBatch();
         if (++batchCounter == helper.getDatabaseAdapter().getMaxBatchSize())
-            helper.executeBatch(objectType);
+            helper.executeBatch(manager.getSchemaMapper().getTableName(ADETable.CTYOBJ_RELATION));
     }
 
     @Override
@@ -65,4 +61,4 @@ public class CityObjectRelationImporter implements ADEImporter {
     public void close() throws CityGMLImportException, SQLException {
         ps.close();
     }
-}
+}
\ No newline at end of file

src/main/java/de/stuttgart/hft/ade/energy3/importer/ImportManager.java

@@ -123,6 +123,8 @@ public class ImportManager implements ADEImportManager {
                 importer = new BuildingPropertiesImporter(connection, helper, this);
             else if (type == AbstractQualifiedAttributeImporter.class)
                 importer = new AbstractQualifiedAttributeImporter(connection, helper, this);
+            else if (type == CityObjectRelationImporter.class)
+                importer = new CityObjectRelationImporter(connection, helper, this);
             else throw new SQLException("Failed to build ADE importer of type " + type.getName() + ".");
 
 

src/main/java/de/stuttgart/hft/ade/energy3/schema/ADESequence.java

@@ -3,6 +3,7 @@ package de.stuttgart.hft.ade.energy3.schema;
 public enum ADESequence {
     //VOLUMETYPE_SEQ,
     //FLOORAREA_SEQ,
+    CTYOBJ_RELATION_SEQ,
     QUALIFIED_ATTRIBUTE_SEQ,
     //HEATEXCHANGETYPE_SEQ,
     //TRANSMITTANCE_SEQ,

src/main/java/de/stuttgart/hft/ade/energy3/schema/ADETable.java

@@ -8,7 +8,7 @@ public enum ADETable {
     BUILDING(BuildingPropertiesImporter.class),
     BUILDING_PARTITION(null),
     CITYOBJECT(CityObjectPropertiesImporter.class),
-    CTYOBJ_RELATION(null),
+    CTYOBJ_RELATION(CityObjectRelationImporter.class),
     DEVICE(AbstractDeviceImporter.class),
     DEVICE_OPERATION(DeviceOperationImporter.class),
     ENERGY_PERF_CERT(EnergyPerformanceCertificateImporter.class),