diff --git a/src/main/java/cn/lunadeer/newbtitle/Commands.java b/src/main/java/cn/lunadeer/newbtitle/Commands.java
index deb2a37..0d26e98 100644
--- a/src/main/java/cn/lunadeer/newbtitle/Commands.java
+++ b/src/main/java/cn/lunadeer/newbtitle/Commands.java
@@ -1,12 +1,15 @@
 package cn.lunadeer.newbtitle;
 
+import cn.lunadeer.newbtitle.utils.Notification;
+import cn.lunadeer.newbtitle.utils.XLogger;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandSender;
 import org.bukkit.command.TabExecutor;
+import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-import java.util.List;
+import java.util.*;
 
 public class Commands implements TabExecutor {
     /**
@@ -23,7 +26,38 @@ public class Commands implements TabExecutor {
      */
     @Override
     public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, @NotNull String[] args) {
-        return false;
+        switch (label) {
+            case "nt":
+                if (args.length == 0) {
+                    if (sender instanceof Player) {
+                        Player player = (Player) sender;
+                        Notification.warn(player, "用法: /nt <use|list|shop|buy>");
+                    } else  {
+                        XLogger.info("用法: /nt <use|list|shop|buy>");
+                    }
+                    return true;
+                }
+                switch (args[0]) {
+                    case "use":
+                        return use(sender, args);
+                    case "list":
+                        return list(sender, args);
+                    case "shop":
+                        return shop(sender, args);
+                    case "buy":
+                        return buy(sender, args);
+                    default:
+                        if (sender instanceof Player) {
+                            Player player = (Player) sender;
+                            Notification.warn(player, "用法: /nt <use|list|shop|buy>");
+                        } else  {
+                            XLogger.info("用法: /nt <use|list|shop|buy>");
+                        }
+                        return true;
+                }
+            default:
+                return false;
+        }
     }
 
     /**
@@ -41,6 +75,101 @@ public class Commands implements TabExecutor {
      */
     @Override
     public @Nullable List<String> onTabComplete(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, @NotNull String[] args) {
-        return null;
+        switch (label) {
+            case "nt":
+                if (args.length == 0) {
+                    return Arrays.asList("use", "list", "shop", "buy");
+                }
+                switch (args[0]) {
+                    case "use":
+                        return Collections.singletonList("要使用的称号ID");
+                    case "list":
+                        return Collections.singletonList("页数(可选)");
+                    case "shop":
+                        return Collections.singletonList("页数(可选)");
+                    case "buy":
+                        return Collections.singletonList("要购买的条目ID");
+                    default:
+                        return Arrays.asList("use", "list", "shop", "buy");
+                }
+            default:
+                return null;
+        }
+    }
+
+    private static boolean use(CommandSender sender, String[] args) {
+        if (!(sender instanceof Player)) {
+            XLogger.warn("该命令只能由玩家执行");
+            return true;
+        }
+        Player player = (Player) sender;
+        if (args.length == 0) {
+            Notification.warn(player, "用法: /nt use <称号ID>");
+            return true;
+        }
+        XPlayer xPlayer = new XPlayer(player);
+        Integer title_id = Integer.parseInt(args[0]);
+        xPlayer.updateUsingTitle(title_id);
+        return true;
+    }
+
+    private static boolean list(CommandSender sender, String[] args) {
+        if (!(sender instanceof Player)) {
+            XLogger.warn("该命令只能由玩家执行");
+            return true;
+        }
+        Player player = (Player) sender;
+        int page = 1;
+        if (args.length != 0) {
+            try {
+                page = Integer.parseInt(args[0]);
+            } catch (Exception e) {
+                Notification.warn(player, "用法: /nt list <页数>");
+                return true;
+            }
+        }
+        XPlayer xPlayer = new XPlayer(player);
+        xPlayer.openBackpack(page);
+        return true;
+    }
+
+    private static boolean shop(CommandSender sender, String[] args) {
+        if (!(sender instanceof Player)) {
+            XLogger.warn("该命令只能由玩家执行");
+            return true;
+        }
+        Player player = (Player) sender;
+        int page = 1;
+        if (args.length != 0) {
+            try {
+                page = Integer.parseInt(args[0]);
+            } catch (Exception e) {
+                Notification.warn(player, "用法: /nt shop <页数>");
+                return true;
+            }
+        }
+        Shop.open(player, page);
+        return true;
+    }
+
+    private static boolean buy(CommandSender sender, String[] args) {
+        if (!(sender instanceof Player)) {
+            XLogger.warn("该命令只能由玩家执行");
+            return true;
+        }
+        Player player = (Player) sender;
+        if (args.length == 0) {
+            Notification.warn(player, "用法: /nt buy <称号ID>");
+            return true;
+        }
+        XPlayer xPlayer = new XPlayer(player);
+        Integer sale_id = Integer.parseInt(args[0]);
+        SaleTitle saleTitle = Shop.getSaleTitle(sale_id);
+        if (saleTitle == null) {
+            Notification.error(player, "该称号不存在");
+            return true;
+        }
+        xPlayer.buyTitle(saleTitle);
+        return true;
     }
 }
diff --git a/src/main/java/cn/lunadeer/newbtitle/Events.java b/src/main/java/cn/lunadeer/newbtitle/Events.java
index 3832aa6..67e7a38 100644
--- a/src/main/java/cn/lunadeer/newbtitle/Events.java
+++ b/src/main/java/cn/lunadeer/newbtitle/Events.java
@@ -1,6 +1,14 @@
 package cn.lunadeer.newbtitle;
 
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerJoinEvent;
 
 public class Events implements Listener {
+
+    @EventHandler
+    public void onPlayerJoin(PlayerJoinEvent event) {
+        new XPlayer(event.getPlayer());
+    }
 }
diff --git a/src/main/java/cn/lunadeer/newbtitle/NewbTitle.java b/src/main/java/cn/lunadeer/newbtitle/NewbTitle.java
index ec9fb7d..4d17355 100644
--- a/src/main/java/cn/lunadeer/newbtitle/NewbTitle.java
+++ b/src/main/java/cn/lunadeer/newbtitle/NewbTitle.java
@@ -1,6 +1,7 @@
 package cn.lunadeer.newbtitle;
 
 import cn.lunadeer.newbtitle.utils.ConfigManager;
+import cn.lunadeer.newbtitle.utils.Database;
 import cn.lunadeer.newbtitle.utils.XLogger;
 import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
@@ -15,6 +16,7 @@ public final class NewbTitle extends JavaPlugin {
         // Plugin startup logic
         instance = this;
         config = new ConfigManager(instance);
+        Database.migrate();
 
         Bukkit.getPluginManager().registerEvents(new Events(), this);
         Objects.requireNonNull(Bukkit.getPluginCommand("NewbTitle")).setExecutor(new Commands());
diff --git a/src/main/java/cn/lunadeer/newbtitle/Shop.java b/src/main/java/cn/lunadeer/newbtitle/Shop.java
index 10c6984..a91bfa9 100644
--- a/src/main/java/cn/lunadeer/newbtitle/Shop.java
+++ b/src/main/java/cn/lunadeer/newbtitle/Shop.java
@@ -34,13 +34,15 @@ public class Shop {
             if (i >= titles.size()) {
                 break;
             }
-            SaleTitle title = titles.get(i);
+            Integer title_sale_id = (Integer) titles.keySet().toArray()[i];
+            TextComponent idx = Component.text("[" + title_sale_id + "] ");
+            SaleTitle title = titles.get(title_sale_id);
             Line line = Line.create();
             TextComponent buy_button = Component.text("购买")
-                    .clickEvent(ClickEvent.clickEvent(ClickEvent.Action.RUN_COMMAND, "/nt shop buy " + title.getId()));
-            line.set(Line.Slot.LEFT, (TextComponent) title.getTitle())
+                    .clickEvent(ClickEvent.clickEvent(ClickEvent.Action.RUN_COMMAND, "/nt shop buy " + title_sale_id));
+            line.set(Line.Slot.LEFT, idx.append(title.getTitle()))
                     .set(Line.Slot.MIDDLE, title.getPrice() + "｜" +
-                            (title.getDays() < 0 ?"∞" : title.getDays()) + "｜" +
+                            (title.getDays() < 0 ? "∞" : title.getDays()) + "｜" +
                             (title.getAmount() < 0 ? "∞" : title.getAmount()))
                     .set(Line.Slot.RIGHT, buy_button);
             view.set(View.Slot.LINE_1, line);
@@ -106,4 +108,32 @@ public class Shop {
         }
         return titles;
     }
+
+    public static SaleTitle getSaleTitle(Integer sale_id) {
+        String sql = "";
+        sql += "SELECT ";
+        sql += "id, ";
+        sql += "title_id, ";
+        sql += "price, ";
+        sql += "days, ";
+        sql += "amount, ";
+        sql += "sale_end_at";
+        sql += "FROM nt_title_shop ";
+        sql += "WHERE id = " + sale_id + ";";
+        ResultSet rs = Database.query(sql);
+        try {
+            if (rs != null && rs.next()) {
+                Integer id = rs.getInt("id");
+                Integer title_id = rs.getInt("title_id");
+                Integer price = rs.getInt("price");
+                Integer days = rs.getInt("days");
+                Integer amount = rs.getInt("amount");
+                Long sale_end_at = rs.getLong("sale_end_at");
+                return new SaleTitle(id, title_id, price, days, amount, sale_end_at);
+            }
+        } catch (Exception e) {
+            XLogger.err("XPlayer getTitles failed: " + e.getMessage());
+        }
+        return null;
+    }
 }
diff --git a/src/main/java/cn/lunadeer/newbtitle/Title.java b/src/main/java/cn/lunadeer/newbtitle/Title.java
index b455dfe..d49ffeb 100644
--- a/src/main/java/cn/lunadeer/newbtitle/Title.java
+++ b/src/main/java/cn/lunadeer/newbtitle/Title.java
@@ -6,6 +6,7 @@ import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.ComponentLike;
 import net.kyori.adventure.text.JoinConfiguration;
 import net.kyori.adventure.text.TextComponent;
+import net.kyori.adventure.text.event.HoverEvent;
 
 import java.sql.ResultSet;
 
@@ -79,7 +80,7 @@ public class Title {
     public Component getTitle() {
         String[] parts = this._title.split("&#");
         TextComponent[] components = new TextComponent[parts.length];
-        if (parts[0].length() > 0) {
+        if (!parts[0].isEmpty()) {
             components[0] = Component.text(parts[0]);
         }
         for (int i = 1; i < parts.length; i++) {
@@ -93,7 +94,7 @@ public class Title {
         TextComponent suffix = Component.text(NewbTitle.config.getSuffix());
         components[0] = prefix.append(components[0]);
         components[parts.length - 1] = components[parts.length - 1].append(suffix);
-        return Component.join(join, components);
+        return Component.join(join, components).hoverEvent(HoverEvent.hoverEvent(HoverEvent.Action.SHOW_TEXT, Component.text(this._description)));
     }
 
     public void setTitle(String title) {
diff --git a/src/main/java/cn/lunadeer/newbtitle/XPlayer.java b/src/main/java/cn/lunadeer/newbtitle/XPlayer.java
index 8f7f67a..1e8418a 100644
--- a/src/main/java/cn/lunadeer/newbtitle/XPlayer.java
+++ b/src/main/java/cn/lunadeer/newbtitle/XPlayer.java
@@ -49,12 +49,14 @@ public class XPlayer {
             if (i >= titles.size()) {
                 break;
             }
-            PlayerTitle title = titles.get(i);
+            int title_id = (int) titles.keySet().toArray()[i];
+            TextComponent idx = Component.text("[" + title_id + "] ");
+            PlayerTitle title = titles.get(title_id);
             Line line = Line.create();
             boolean is_using = Objects.equals(title.getId(), _current_title_id);
             TextComponent buy_button = Component.text(is_using ? "卸下" : "使用")
                     .clickEvent(ClickEvent.clickEvent(ClickEvent.Action.RUN_COMMAND, "/nt use " + (is_using ? -1 : title.getId())));
-            line.set(Line.Slot.LEFT, (TextComponent) title.getTitle())
+            line.set(Line.Slot.LEFT, idx.append(title.getTitle()))
                     .set(Line.Slot.MIDDLE, title.getExpireAt())
                     .set(Line.Slot.RIGHT, buy_button);
             view.set(View.Slot.LINE_1, line);
@@ -75,11 +77,10 @@ public class XPlayer {
         applyCurrentTitle();
         String sql = "";
         sql += "UPDATE nt_player_using_title ";
-        sql += "SET title_id = " + title_id + ", ";
+        sql += "SET title_id = " + _current_title_id + ", ";
         sql += "updated_at = CURRENT_TIMESTAMP ";
         sql += "WHERE uuid = '" + _player.getUniqueId().toString() + "';";
         Database.query(sql);
-        _current_title_id = title_id;
         Notification.info(_player, "成功使用称号: " + _titles.get(title_id).getTitle());
     }