diff --git a/app/db/mongdb.ts b/app/db/mongdb.ts
index 5f82f5c99..ac2e4e65e 100644
--- a/app/db/mongdb.ts
+++ b/app/db/mongdb.ts
@@ -1,28 +1,35 @@
-// 引入 `MongoClient` 类型，以便于类型注解
-import { MongoClient, MongoClientOptions } from "mongodb";
+import { MongoClient } from "mongodb";
 
-// 使用 `process.env.MONGODB_URI` 的值初始化 URI 变量
-const uri: string | undefined = process.env.MONGODB_URI;
-// 定义 MongoClient 选项对象
-const options: MongoClientOptions = {};
+const uri = process.env.MONGODB_URI as string; // your mongodb connection string
+const options = {};
 
-// 声明 client 和 clientPromise 变量，类型分别为 MongoClient 和 Promise<MongoClient>
-let client: MongoClient;
-let clientPromise: Promise<MongoClient>;
-
-// 判断当前环境是否为开发环境
-if (process.env.NODE_ENV === "development") {
-  // 在开发模式下，使用全局变量，以便在 HMR (Hot Module Replacement) 导致的模块重新加载时保留值。
-  if (!global._mongoClientPromise) {
-    client = new MongoClient(uri!, options); // 使用非空断言运算符（!），因为我们已经检查了 uri 是否存在
-    global._mongoClientPromise = client.connect();
-  }
-  clientPromise = global._mongoClientPromise;
-} else {
-  // 在生产模式下，最好不要使用全局变量。
-  client = new MongoClient(uri!, options); // 使用非空断言运算符（!），因为我们已经检查了 uri 是否存在
-  clientPromise = client.connect();
+declare global {
+  var _mongoClientPromise: Promise<MongoClient>;
 }
 
-// 导出模块作用域的 MongoClient promise。通过在一个单独的模块中这样做，client 可以在函数之间共享。
+class Singleton {
+  private static _instance: Singleton;
+  private client: MongoClient;
+  private clientPromise: Promise<MongoClient>;
+  private constructor() {
+    this.client = new MongoClient(uri, options);
+    this.clientPromise = this.client.connect();
+    if (process.env.NODE_ENV === "development") {
+      // In development mode, use a global variable so that the value
+      // is preserved across module reloads caused by HMR (Hot Module Replacement).
+      global._mongoClientPromise = this.clientPromise;
+    }
+  }
+
+  public static get instance() {
+    if (!this._instance) {
+      this._instance = new Singleton();
+    }
+    return this._instance.clientPromise;
+  }
+}
+const clientPromise = Singleton.instance;
+
+// Export a module-scoped MongoClient promise. By doing this in a
+// separate module, the client can be shared across functions.
 export default clientPromise;