=== modified file 'dhis-2/dhis-api/src/main/java/org/hisp/dhis/feedback/ErrorCode.java'
--- dhis-2/dhis-api/src/main/java/org/hisp/dhis/feedback/ErrorCode.java	2016-03-03 05:13:32 +0000
+++ dhis-2/dhis-api/src/main/java/org/hisp/dhis/feedback/ErrorCode.java	2016-03-13 10:19:38 +0000
@@ -54,7 +54,8 @@
     /* Preheat Errors */
     E5000( "Found matching object for given reference, but import mode is CREATE. Identifier was {0}, and object was {1}." ),
     E5001( "No matching object for given reference. Identifier was {0}, and object was {1}." ),
-    E5002( "Invalid reference {0} on object {1} for association \"{2}\"." );
+    E5002( "Invalid reference {0} on object {1} for association \"{2}\"." ),
+    E5003( "Property \"{0}\" with value \"{1}\" on object {2} already exists on object {3}." );
 
     private String message;
 

=== modified file 'dhis-2/dhis-api/src/main/java/org/hisp/dhis/preheat/Preheat.java'
--- dhis-2/dhis-api/src/main/java/org/hisp/dhis/preheat/Preheat.java	2016-03-12 09:00:34 +0000
+++ dhis-2/dhis-api/src/main/java/org/hisp/dhis/preheat/Preheat.java	2016-03-13 10:19:38 +0000
@@ -55,6 +55,8 @@
 
     private Map<String, UserCredentials> usernames = new HashMap<>();
 
+    private Map<Class<? extends IdentifiableObject>, Map<String, Map<Object, String>>> uniquenessMap = new HashMap<>();
+
     public Preheat()
     {
     }
@@ -309,4 +311,14 @@
 
         return klass;
     }
+
+    public void setUniquenessMap( Map<Class<? extends IdentifiableObject>, Map<String, Map<Object, String>>> uniquenessMap )
+    {
+        this.uniquenessMap = uniquenessMap;
+    }
+
+    public Map<Class<? extends IdentifiableObject>, Map<String, Map<Object, String>>> getUniquenessMap()
+    {
+        return uniquenessMap;
+    }
 }

=== modified file 'dhis-2/dhis-api/src/main/java/org/hisp/dhis/preheat/PreheatIdentifier.java'
--- dhis-2/dhis-api/src/main/java/org/hisp/dhis/preheat/PreheatIdentifier.java	2016-03-12 09:00:34 +0000
+++ dhis-2/dhis-api/src/main/java/org/hisp/dhis/preheat/PreheatIdentifier.java	2016-03-13 10:19:38 +0000
@@ -97,9 +97,9 @@
 
         if ( name == null )
         {
-            return identifiers.toString();
+            return identifiers.toString() + " (" + object.getClass().getSimpleName() + ")";
         }
 
-        return name + " " + identifiers.toString();
+        return name + " " + identifiers.toString() + " (" + object.getClass().getSimpleName() + ")";
     }
 }

=== modified file 'dhis-2/dhis-api/src/main/java/org/hisp/dhis/preheat/PreheatParams.java'
--- dhis-2/dhis-api/src/main/java/org/hisp/dhis/preheat/PreheatParams.java	2016-03-04 11:51:15 +0000
+++ dhis-2/dhis-api/src/main/java/org/hisp/dhis/preheat/PreheatParams.java	2016-03-13 10:19:38 +0000
@@ -1,6 +1,14 @@
 package org.hisp.dhis.preheat;
 
 import com.google.common.base.MoreObjects;
+import org.hisp.dhis.common.IdentifiableObject;
+import org.hisp.dhis.user.User;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
 
 /*
  * Copyright (c) 2004-2016, University of Oslo
@@ -30,14 +38,6 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-import org.hisp.dhis.common.IdentifiableObject;
-import org.hisp.dhis.user.User;
-
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Set;
-
 /**
  * @author Morten Olav Hansen <mortenoh@gmail.com>
  */
@@ -53,6 +53,8 @@
 
     private Map<PreheatIdentifier, Map<Class<? extends IdentifiableObject>, Set<String>>> references = new HashMap<>();
 
+    private Map<Class<? extends IdentifiableObject>, List<IdentifiableObject>> objects = new HashMap<>();
+
     public PreheatParams()
     {
     }
@@ -100,6 +102,16 @@
         return this;
     }
 
+    public Map<Class<? extends IdentifiableObject>, List<IdentifiableObject>> getObjects()
+    {
+        return objects;
+    }
+
+    public void setObjects( Map<Class<? extends IdentifiableObject>, List<IdentifiableObject>> objects )
+    {
+        this.objects = objects;
+    }
+
     public Map<PreheatIdentifier, Map<Class<? extends IdentifiableObject>, Set<String>>> getReferences()
     {
         return references;
@@ -111,7 +123,6 @@
         return this;
     }
 
-
     @Override
     public String toString()
     {

=== modified file 'dhis-2/dhis-api/src/main/java/org/hisp/dhis/preheat/PreheatService.java'
--- dhis-2/dhis-api/src/main/java/org/hisp/dhis/preheat/PreheatService.java	2016-03-13 08:51:26 +0000
+++ dhis-2/dhis-api/src/main/java/org/hisp/dhis/preheat/PreheatService.java	2016-03-13 10:19:38 +0000
@@ -80,6 +80,14 @@
      */
     Map<PreheatIdentifier, Map<Class<? extends IdentifiableObject>, Set<String>>> collectReferences( Map<Class<? extends IdentifiableObject>, List<IdentifiableObject>> objects );
 
+    /**
+     * Scan objects and collect unique values (used to verify object properties with unique=true)
+     *
+     * @param objects Objects to scan
+     * @return Klass -> Property.name -> Value -> UID
+     */
+    Map<Class<? extends IdentifiableObject>, Map<String, Map<Object, String>>> collectUniqueness( Map<Class<? extends IdentifiableObject>, List<IdentifiableObject>> objects );
+
     Map<Class<?>, Map<String, Map<String, Object>>> collectObjectReferences( Map<Class<? extends IdentifiableObject>, List<IdentifiableObject>> objects );
 
     /**
@@ -103,10 +111,11 @@
     /**
      * Check for properties that are unique.
      *
-     * @param objects Object to check
-     * @param preheat Preheat Cache to use
+     * @param objects    Object to check
+     * @param preheat    Preheat Cache to use
+     * @param identifier Use this identifier type report issues
      */
-    List<ObjectErrorReport> checkUniqueness( List<IdentifiableObject> objects, Preheat preheat );
+    List<ObjectErrorReport> checkUniqueness( List<IdentifiableObject> objects, Preheat preheat, PreheatIdentifier identifier );
 
     /**
      * Check for properties that are unique.
@@ -114,7 +123,7 @@
      * @param object  Object to check
      * @param preheat Preheat Cache to use
      */
-    List<ErrorReport> checkUniqueness( IdentifiableObject object, Preheat preheat );
+    List<ErrorReport> checkUniqueness( IdentifiableObject object, Preheat preheat, PreheatIdentifier identifier );
 
     /**
      * Connects id object references on a given object using a given identifier + a preheated Preheat cache.

=== modified file 'dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/preheat/DefaultPreheatService.java'
--- dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/preheat/DefaultPreheatService.java	2016-03-13 08:52:19 +0000
+++ dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/preheat/DefaultPreheatService.java	2016-03-13 10:19:38 +0000
@@ -161,6 +161,35 @@
             }
         }
 
+        Set<Class<? extends IdentifiableObject>> klasses = new HashSet<>();
+
+        if ( params.getReferences().containsKey( PreheatIdentifier.UID ) )
+        {
+            klasses.addAll( params.getReferences().get( PreheatIdentifier.UID ).keySet() );
+        }
+
+        if ( params.getReferences().containsKey( PreheatIdentifier.CODE ) )
+        {
+            klasses.addAll( params.getReferences().get( PreheatIdentifier.CODE ).keySet() );
+        }
+
+        Map<Class<? extends IdentifiableObject>, List<IdentifiableObject>> uniqueCollectionMap = new HashMap<>();
+
+        // TODO fix this, should be part of main preheat process, this will slow things down.. but we need all objects to check for uniqueness
+        for ( Class<? extends IdentifiableObject> klass : klasses )
+        {
+            Query query = Query.from( schemaService.getDynamicSchema( klass ) );
+            query.setUser( preheat.getUser() );
+            List<? extends IdentifiableObject> objects = queryService.query( query );
+
+            if ( !objects.isEmpty() )
+            {
+                uniqueCollectionMap.put( klass, new ArrayList<>( objects ) );
+            }
+        }
+
+        preheat.setUniquenessMap( collectUniqueness( uniqueCollectionMap ) );
+
         return preheat;
     }
 
@@ -370,11 +399,51 @@
                 if ( uidMap.get( UserGroup.class ).isEmpty() ) uidMap.remove( UserGroup.class );
                 if ( codeMap.get( UserGroup.class ).isEmpty() ) codeMap.remove( UserGroup.class );
             }
-
+        }
+
+        return map;
+    }
+
+    @Override
+    @SuppressWarnings( "unchecked" )
+    public Map<Class<? extends IdentifiableObject>, Map<String, Map<Object, String>>> collectUniqueness( Map<Class<? extends IdentifiableObject>, List<IdentifiableObject>> objects )
+    {
+        Map<Class<? extends IdentifiableObject>, Map<String, Map<Object, String>>> uniqueMap = new HashMap<>();
+
+        if ( objects.isEmpty() )
+        {
+            return uniqueMap;
+        }
+
+        Map<Class<? extends IdentifiableObject>, List<IdentifiableObject>> scanObjects = new HashMap<>();
+        scanObjects.putAll( objects ); // clone objects list, we don't want to modify it
+
+        if ( scanObjects.containsKey( User.class ) )
+        {
+            List<IdentifiableObject> users = scanObjects.get( User.class );
+            List<IdentifiableObject> userCredentials = new ArrayList<>();
+
+            for ( IdentifiableObject identifiableObject : users )
+            {
+                User user = (User) identifiableObject;
+
+                if ( user.getUserCredentials() != null )
+                {
+                    userCredentials.add( user.getUserCredentials() );
+                }
+            }
+
+            scanObjects.put( UserCredentials.class, userCredentials );
+        }
+
+        for ( Class<? extends IdentifiableObject> objectClass : scanObjects.keySet() )
+        {
+            Schema schema = schemaService.getDynamicSchema( objectClass );
+            List<IdentifiableObject> identifiableObjects = scanObjects.get( objectClass );
             uniqueMap.put( objectClass, handleUniqueProperties( schema, identifiableObjects ) );
         }
 
-        return map;
+        return uniqueMap;
     }
 
     private Map<String, Map<Object, String>> handleUniqueProperties( Schema schema, List<IdentifiableObject> objects )
@@ -594,7 +663,7 @@
     }
 
     @Override
-    public List<ObjectErrorReport> checkUniqueness( List<IdentifiableObject> objects, Preheat preheat )
+    public List<ObjectErrorReport> checkUniqueness( List<IdentifiableObject> objects, Preheat preheat, PreheatIdentifier identifier )
     {
         List<ObjectErrorReport> objectErrorReports = new ArrayList<>();
 
@@ -606,7 +675,7 @@
         for ( int i = 0; i < objects.size(); i++ )
         {
             IdentifiableObject object = objects.get( i );
-            List<ErrorReport> errorReports = checkUniqueness( object, preheat );
+            List<ErrorReport> errorReports = checkUniqueness( object, preheat, identifier );
 
             if ( errorReports.isEmpty() ) continue;
 
@@ -620,14 +689,41 @@
     }
 
     @Override
-    public List<ErrorReport> checkUniqueness( IdentifiableObject object, Preheat preheat )
+    public List<ErrorReport> checkUniqueness( IdentifiableObject object, Preheat preheat, PreheatIdentifier identifier )
     {
         List<ErrorReport> errorReports = new ArrayList<>();
 
-        if ( object == null )
-        {
-            return errorReports;
-        }
+        if ( object == null || Preheat.isDefault( object ) ) return errorReports;
+
+        Map<String, Map<Object, String>> uniquenessMap = preheat.getUniquenessMap().get( object.getClass() );
+
+        if ( uniquenessMap == null ) return errorReports;
+
+        Schema schema = schemaService.getDynamicSchema( object.getClass() );
+        List<Property> uniqueProperties = schema.getProperties().stream()
+            .filter( p -> p.isPersisted() && p.isOwner() && p.isUnique() )
+            .collect( Collectors.toList() );
+
+        uniqueProperties.forEach( property -> {
+            Object value = ReflectionUtils.invokeMethod( object, property.getGetterMethod() );
+
+            if ( value != null )
+            {
+                if ( uniquenessMap.containsKey( property.getName() ) && !uniquenessMap.get( property.getName() ).isEmpty() )
+                {
+                    String persistedUid = uniquenessMap.get( property.getName() ).get( value );
+
+                    if ( persistedUid != null )
+                    {
+                        if ( !object.getUid().equals( persistedUid ) )
+                        {
+                            errorReports.add( new ErrorReport( object.getClass(), ErrorCode.E5003, property.getName(), value,
+                                identifier.getIdentifiersWithName( object ), persistedUid ) );
+                        }
+                    }
+                }
+            }
+        } );
 
         return errorReports;
     }

=== modified file 'dhis-2/dhis-services/dhis-service-dxf2/src/main/java/org/hisp/dhis/dxf2/metadata2/objectbundle/DefaultObjectBundleService.java'
--- dhis-2/dhis-services/dhis-service-dxf2/src/main/java/org/hisp/dhis/dxf2/metadata2/objectbundle/DefaultObjectBundleService.java	2016-03-13 08:51:26 +0000
+++ dhis-2/dhis-services/dhis-service-dxf2/src/main/java/org/hisp/dhis/dxf2/metadata2/objectbundle/DefaultObjectBundleService.java	2016-03-13 10:19:38 +0000
@@ -105,6 +105,7 @@
         }
 
         preheatParams.setUser( params.getUser() );
+        preheatParams.setObjects( params.getObjects() );
 
         if ( PreheatMode.REFERENCE == preheatParams.getPreheatMode() )
         {
@@ -164,7 +165,8 @@
                 objectBundleValidation.addObjectErrorReports( validateBySchemas( klass, bundle.getObjectMap().get( klass ), bundle ) );
                 objectBundleValidation.addObjectErrorReports( preheatService.checkReferences( bundle.getObjectMap().get( klass ),
                     bundle.getPreheat(), bundle.getPreheatIdentifier() ) );
-                objectBundleValidation.addObjectErrorReports( preheatService.checkUniqueness( bundle.getObjectMap().get( klass ), bundle.getPreheat() ) );
+                objectBundleValidation.addObjectErrorReports( preheatService.checkUniqueness( bundle.getObjectMap().get( klass ), bundle.getPreheat(),
+                    bundle.getPreheatIdentifier() ) );
             }
 
             if ( bundle.getImportMode().isCreate() )
@@ -173,7 +175,8 @@
                 objectBundleValidation.addObjectErrorReports( validateBySchemas( klass, bundle.getObjects( klass, false ), bundle ) );
                 objectBundleValidation.addObjectErrorReports( preheatService.checkReferences( bundle.getObjectMap().get( klass ),
                     bundle.getPreheat(), bundle.getPreheatIdentifier() ) );
-                objectBundleValidation.addObjectErrorReports( preheatService.checkUniqueness( bundle.getObjectMap().get( klass ), bundle.getPreheat() ) );
+                objectBundleValidation.addObjectErrorReports( preheatService.checkUniqueness( bundle.getObjectMap().get( klass ), bundle.getPreheat(),
+                    bundle.getPreheatIdentifier() ) );
             }
 
             if ( bundle.getImportMode().isUpdate() )
@@ -182,7 +185,8 @@
                 objectBundleValidation.addObjectErrorReports( validateBySchemas( klass, bundle.getObjects( klass, true ), bundle ) );
                 objectBundleValidation.addObjectErrorReports( preheatService.checkReferences( bundle.getObjectMap().get( klass ),
                     bundle.getPreheat(), bundle.getPreheatIdentifier() ) );
-                objectBundleValidation.addObjectErrorReports( preheatService.checkUniqueness( bundle.getObjectMap().get( klass ), bundle.getPreheat() ) );
+                objectBundleValidation.addObjectErrorReports( preheatService.checkUniqueness( bundle.getObjectMap().get( klass ), bundle.getPreheat(),
+                    bundle.getPreheatIdentifier() ) );
             }
 
             if ( bundle.getImportMode().isDelete() )

=== modified file 'dhis-2/dhis-services/dhis-service-dxf2/src/test/java/org/hisp/dhis/dxf2/metadata2/objectbundle/ObjectBundleServiceTest.java'
--- dhis-2/dhis-services/dhis-service-dxf2/src/test/java/org/hisp/dhis/dxf2/metadata2/objectbundle/ObjectBundleServiceTest.java	2016-03-13 07:52:55 +0000
+++ dhis-2/dhis-services/dhis-service-dxf2/src/test/java/org/hisp/dhis/dxf2/metadata2/objectbundle/ObjectBundleServiceTest.java	2016-03-13 10:19:38 +0000
@@ -64,7 +64,6 @@
 import org.hisp.dhis.user.UserGroup;
 import org.hisp.dhis.user.UserService;
 import org.hisp.dhis.validation.ValidationRule;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.core.io.ClassPathResource;
@@ -1371,7 +1370,6 @@
     }
 
     @Test
-    @Ignore
     public void testCreateMetadataWithSuperuserRoleInjected() throws IOException
     {
         createUserAndInjectSecurityContext( true );
@@ -1385,8 +1383,10 @@
         params.setObjects( metadata );
 
         ObjectBundle bundle = objectBundleService.create( params );
-        assertTrue( objectBundleService.validate( bundle ).getObjectErrorReports().isEmpty() );
-        objectBundleService.commit( bundle );
+        ObjectBundleValidation validate = objectBundleService.validate( bundle );
+
+        assertFalse( validate.getObjectErrorReports().isEmpty() );
+        assertEquals( 1, validate.getErrorReportsByCode( UserAuthorityGroup.class, ErrorCode.E5003 ).size() );
     }
 
     private void defaultSetup()