创建并连接数据库，并修改登录和注册接口

node_modules/mysql2/typings/mysql/lib/PoolConnection.d.ts

@@ -0,0 +1,16 @@
+import { Connection } from './Connection.js';
+import { PoolConnection as PromisePoolConnection } from '../../../promise.js';
+
+declare class PoolConnection extends Connection {
+  connection: Connection;
+  release(): void;
+  [Symbol.dispose](): void;
+  /**
+   * Returns a promise-based wrapper around this pooled connection.
+   *
+   * Note: this resolves to a `PoolConnection` from `mysql2/promise`, not to a `Pool`.
+   */
+  promise(promiseImpl?: PromiseConstructor): PromisePoolConnection;
+}
+
+export { PoolConnection };