创建并连接数据库，并修改登录和注册接口

node_modules/mysql2/lib/commands/reset_connection.js

@@ -0,0 +1,29 @@
+'use strict';
+
+const Command = require('./command');
+const Packets = require('../packets/index.js');
+
+class ResetConnection extends Command {
+  constructor(callback) {
+    super();
+    this.onResult = callback;
+  }
+
+  start(packet, connection) {
+    const req = new Packets.ResetConnection();
+    connection.writePacket(req.toPacket());
+    return ResetConnection.prototype.resetConnectionResponse;
+  }
+
+  resetConnectionResponse(packet, connection) {
+    if (connection._statements) {
+      connection._statements.clear();
+    }
+    if (this.onResult) {
+      process.nextTick(this.onResult.bind(this, null));
+    }
+    return null;
+  }
+}
+
+module.exports = ResetConnection;