--- a/artifact-database/src/main/java/de/intevation/artifactdatabase/Backend.java	Wed Mar 02 16:02:47 2011 +0000
+++ b/artifact-database/src/main/java/de/intevation/artifactdatabase/Backend.java	Wed Mar 02 17:43:25 2011 +0000
@@ -94,6 +94,9 @@
     public static final String SQL_USERS_INSERT =
         SQL.get("users.insert");
 
+    public static final String SQL_USERS_SELECT_ID_BY_GID =
+        SQL.get("users.select.id.by.gid");
+
     public static final String SQL_USERS_SELECT_GID =
         SQL.get("users.select.gid");
 
@@ -106,6 +109,27 @@
     public static final String SQL_USER_SELECT_ALL =
         SQL.get("users.select.all");
 
+    public static final String SQL_USERS_COLLECTIONS =
+        SQL.get("users.collections");
+
+    public static final String SQL_USERS_COLLECTION_IDS =
+        SQL.get("users.collection.ids");
+
+    public static final String SQL_USERS_DELETE_ALL_COLLECTIONS =
+        SQL.get("users.delete.all.collections");
+
+    public static final String SQL_ARTIFACTS_IN_ONLY_COLLECTION_ONLY =
+        SQL.get("artifacts.in.one.collection.only");
+
+    public static final String SQL_OUTDATE_ARTIFACTS_COLLECTION =
+        SQL.get("outdate.artifacts.collection");
+
+    public static final String SQL_OUTDATE_ARTIFACTS_USER =
+        SQL.get("outdate.artifacts.user");
+
+    public static final String SQL_DELETE_USER_COLLECTION_ITEMS =
+        SQL.get("delete.user.collection.items");
+
     /** The singleton.*/
     protected static Backend instance;
 
@@ -870,7 +894,87 @@
     }
 
     public void deleteUser(User user) {
-        // TODO: implement me!
+
+        Connection        conn  = null;
+        ResultSet         result      = null;
+        PreparedStatement stmnt       = null;
+
+        String identifier = user.identifier();
+
+        DataSource dataSource = DBConnection.getDataSource();
+        try {
+            conn = dataSource.getConnection();
+            try {
+                conn.setAutoCommit(false);
+
+                // fetch user id
+                stmnt = conn.prepareStatement(SQL_USERS_SELECT_ID_BY_GID);
+
+                stmnt.setString(1, identifier);
+                result = stmnt.executeQuery();
+
+                if (!result.next()) { // No such user
+                    return;
+                }
+
+                int id = result.getInt(1);
+
+                result.close(); result = null;
+                stmnt.close();  stmnt  = null;
+
+                // outdate the artifacts exclusively used by the user
+
+                stmnt = conn.prepareStatement(SQL_OUTDATE_ARTIFACTS_USER);
+                stmnt.setInt(1, id);
+                stmnt.setInt(2, id);
+                stmnt.execute();
+
+                stmnt.close(); stmnt = null;
+
+                // delete the collection items of the user
+
+                stmnt = conn.prepareStatement(SQL_DELETE_USER_COLLECTION_ITEMS);
+                stmnt.setInt(1, id);
+                stmnt.execute();
+                stmnt.close(); stmnt = null;
+
+                // delete the collections of the user
+
+                stmnt = conn.prepareStatement(SQL_USERS_COLLECTIONS);
+                stmnt.setInt(1, id);
+                stmnt.execute();
+                stmnt.close(); stmnt = null;
+
+                // delete the user
+
+                stmnt = conn.prepareStatement(SQL_USERS_DELETE_ID);
+                stmnt.setInt(1, id);
+                stmnt.execute();
+
+                conn.commit();
+            }
+            catch (SQLException sqle) {
+                conn.rollback();
+                throw sqle;
+            }
+        }
+        catch (SQLException sqle) {
+            logger.error(sqle.getLocalizedMessage(), sqle);
+        }
+        finally {
+            if (result != null) {
+                try { result.close(); }
+                catch (SQLException sqle) {}
+            }
+            if (stmnt != null) {
+                try { stmnt.close(); }
+                catch (SQLException sqle) {}
+            }
+            if (conn != null) {
+                try { conn.close(); }
+                catch (SQLException sqle) {}
+            }
+        }
     }
 
     public User getUser(String identifier) {