diff -r 6eede6088d41 -r 3f30adba1c63 src/main/java/de/uapcore/lightpit/dao/Functions.java
--- a/src/main/java/de/uapcore/lightpit/dao/Functions.java	Sun Dec 20 11:06:25 2020 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,101 +0,0 @@
-/*
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
- *
- * Copyright 2018 Mike Becker. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- *   1. Redistributions of source code must retain the above copyright
- *      notice, this list of conditions and the following disclaimer.
- *
- *   2. Redistributions in binary form must reproduce the above copyright
- *      notice, this list of conditions and the following disclaimer in the
- *      documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- *
- */
-package de.uapcore.lightpit.dao;
-
-import java.sql.*;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Optional;
-import java.util.function.Function;
-
-/**
- * Some DAO utilities.
- */
-public final class Functions {
-
-    public static String getSafeString(ResultSet rs, String column) throws SQLException {
-        return Optional.ofNullable(rs.getString(column)).orElse("");
-    }
-
-    public static void setStringOrNull(PreparedStatement stmt, int index, String str) throws SQLException {
-        if (str == null || str.isBlank()) {
-            stmt.setNull(index, Types.VARCHAR);
-        } else {
-            stmt.setString(index, str);
-        }
-    }
-
-    public static void setDateOrNull(PreparedStatement stmt, int index, Date date) throws SQLException {
-        if (date == null) {
-            stmt.setNull(index, Types.DATE);
-        } else {
-            stmt.setDate(index, date);
-        }
-    }
-
-    public static <T> void setForeignKeyOrNull(PreparedStatement stmt, int index, T instance, Function<? super T, Integer> keyGetter) throws SQLException {
-        Integer key = Optional.ofNullable(instance).map(keyGetter).orElse(null);
-        if (key == null) {
-            stmt.setNull(index, Types.INTEGER);
-        } else {
-            stmt.setInt(index, key);
-        }
-    }
-
-    @FunctionalInterface
-    public interface ResultSetMapper<T> {
-        T apply(ResultSet rs) throws SQLException;
-    }
-
-    public static <T> List<T> list(PreparedStatement stmt, ResultSetMapper<T> mapper) throws SQLException {
-        List<T> results = new ArrayList<>();
-        try (var result = stmt.executeQuery()) {
-            while (result.next()) {
-                final var project = mapper.apply(result);
-                results.add(project);
-            }
-        }
-        return results;
-    }
-
-    public static <T> T find(PreparedStatement stmt, ResultSetMapper<T> mapper) throws SQLException {
-        try (var result = stmt.executeQuery()) {
-            if (result.next()) {
-                final var ent = mapper.apply(result);
-                return ent;
-            } else {
-                return null;
-            }
-        }
-    }
-
-    private Functions() {
-
-    }
-}