创建并连接数据库，并修改登录和注册接口

node_modules/mysql2/lib/commands/close_statement.js

@@ -0,0 +1,18 @@
+'use strict';
+
+const Command = require('./command');
+const Packets = require('../packets/index.js');
+
+class CloseStatement extends Command {
+  constructor(id) {
+    super();
+    this.id = id;
+  }
+
+  start(packet, connection) {
+    connection.writePacket(new Packets.CloseStatement(this.id).toPacket(1));
+    return null;
+  }
+}
+
+module.exports = CloseStatement;