创建并连接数据库，并修改登录和注册接口

node_modules/mysql2/lib/packets/prepared_statement_header.js

@@ -0,0 +1,16 @@
+'use strict';
+
+class PreparedStatementHeader {
+  constructor(packet) {
+    packet.skip(1); // should be 0
+    this.id = packet.readInt32();
+    this.fieldCount = packet.readInt16();
+    this.parameterCount = packet.readInt16();
+    packet.skip(1); // should be 0
+    this.warningCount = packet.readInt16();
+  }
+}
+
+// TODO: toPacket
+
+module.exports = PreparedStatementHeader;