.env文件：

MONGODB_URI=mongodb+srv://<username>:<password>@<cluster>.puuwipp.mongodb.net/<db1>
MONGODB_URI_ADMIN=mongodb+srv://<username>:<password>@<cluster>.puuwipp.mongodb.net/<db2>

nuxt.config.ts:

runtimeConfig: {
    mongodbUri: process.env.MONGODB_URI,
    mongodbUriAdmin: process.env.MONGODB_URI_ADMIN,
  }

server.index.ts:

export default async (_nitroApp: Nitro) => {
  const config = useRuntimeConfig();

  try {
    mongoose.set("strictQuery", false);
    await mongoose.connect(config.mongodbUri);
    console.log("DB connection established");
    await mongoose.connect(config.mongodbUriAdmin);
    console.log("ADMIN DB connection established");
  } catch (e) {
    return e.message;
  }
};

但是我不知道，如何定义在 Mongoose 模型/服务器请求中使用哪个数据库