--- a/artifact-database/src/main/java/de/intevation/artifactdatabase/Backend.java	Sun Mar 06 10:27:16 2011 +0000
+++ b/artifact-database/src/main/java/de/intevation/artifactdatabase/Backend.java	Sun Mar 06 10:55:37 2011 +0000
@@ -167,6 +167,12 @@
     public static final String SQL_COLLECTION_ITEM_GET_ATTRIBUTE =
         SQL.get("collection.item.get.attribute");
 
+    public static final String SQL_COLLECTION_ITEM_SET_ATTRIBUTE =
+        SQL.get("collection.item.set.attribute");
+
+    public static final String SQL_COLLECTIONS_TOUCH_BY_GID =
+        SQL.get("collections.touch.by,gid");
+
     /** The singleton.*/
     protected static Backend instance;
 
@@ -1121,6 +1127,7 @@
         }
         if (!isValidIdentifier(artifactId)) {
             logger.debug("artifact id is not valid: " + artifactId);
+            return null;
         }
 
         final Document [] document = new Document[1];
@@ -1144,12 +1151,46 @@
     }
 
     public boolean setCollectionAttribute(
-        String collectionId, 
-        String artifactId,
-        Document attribute
+        final String   collectionId, 
+        final String   artifactId,
+        Document       attribute
     ) {
-        // TODO: Implement me!
-        return false;
+        if (!isValidIdentifier(collectionId)) {
+            logger.debug("collection id is not valid: " + collectionId);
+            return false;
+        }
+        if (!isValidIdentifier(artifactId)) {
+            logger.debug("artifact id is not valid: " + artifactId);
+            return false;
+        }
+
+        final byte [] data = XMLUtils.toByteArray(attribute);
+
+        return new SQLExecutor() {
+            public boolean doIt() throws SQLException {
+
+                // set the column in collection items
+                prepareStatement(SQL_COLLECTION_ITEM_SET_ATTRIBUTE);
+                if (data == null) {
+                    stmnt.setNull(1, Types.BINARY);
+                }
+                else {
+                    stmnt.setBytes(1, data);
+                }
+                stmnt.setString(2, collectionId);
+                stmnt.setString(3, artifactId);
+                stmnt.execute();
+                reset();
+
+                // touch the collection
+                prepareStatement(SQL_COLLECTIONS_TOUCH_BY_GID);
+                stmnt.setString(1, collectionId);
+                stmnt.execute();
+
+                conn.commit();
+                return true;
+            }
+        }.runWrite();
     }
 
     public boolean addCollectionArtifact(