Question

我正在使用这种方法：

public static boolean match(String name, String password) {
                ResultSet result = null;
                try {
                        result = World.database().executeQuery("SELECT password FROM " + PLAYER_TABLE + " WHERE username='" + name + "'");
                        if (result.next()) {
                                String passwordResult = result.getString("password");
                                String encryptedPassword = MD5Encryption.encrypt(password);
                                if (encryptedPassword.equals(passwordResult))
                                        return true;
                        } else {
                                System.out.println("match(String name, String password: false.");
                                StringBuilder query = new StringBuilder();
                                query.append("INSERT INTO `frostblades_users` (id, username, displayName, previousname, lastChanged, password, email, reg_ip, reg_date, last_ip, last_online, picture, rights, playTime, forum, gender, donator, donatorTill, mute, muteTill, banned, online, sof_points, location, hitpoints, inventory_items, inventory_amount, equipment_items, equipment_amount, bank_items, bank_amount, bank_tabs, skills_level, skills_experience, looks, colours, points, friends, ignores, quest_points, music, prayer_points, pouch, run_energy, magic_book, prayer_book, familiar, bob_items, bob_amount, quest_states, quest_progress) VALUES(");
                                query.append("'" + player().definition().index() + "'").append(",");
                                query.append("'" + log.type().index() + "'").append(",");
                                query.append("'" + log.key() + "'").append(",");
                                query.append("'" + log.value() + "'").append(",");
                                query.append("'" + log.date() + "'").append(")");
                                World.database().executeUpdate(query.toString());
                        }

现在我以冒险日志为例：

StringBuilder query = new StringBuilder();
                                query.append("INSERT INTO `frostblades_adventurers_logs` (user_id, log_type, log_key, log_value, log_date) VALUES(");
                                query.append("'" + player().definition().index() + "'").append(",");
                                query.append("'" + log.type().index() + "'").append(",");
                                query.append("'" + log.key() + "'").append(",");
                                query.append("'" + log.value() + "'").append(",");
                                query.append("'" + log.date() + "'").append(")");
                                World.database().executeUpdate(query.toString());

我如何获得“player（）。definition（）。index（）”这是为每个新帐户增加++的ID？

Answer 1

要检查用户名是否存在，您可以执行如下查询：

  SELECT Count(*) as numusers FROM users WHERE username = 'THEUSERNAME';

如果生成的numusers＆gt; 0然后用户名存在，否则不存在。因此，您需要使用查询构建器来创建和执行查询。

对于ID，最简单的方法是让数据库增加id，因此不要在数据库中插入id。

Java，SQL，id增量语句？

1 个答案: