使用 mongoose 切换数据库

您好，有没有办法用 mongoose 切换数据库？ 我想我可以这样做：

mongoose.disconnect();
mongoose.connect('localhost',db);

但它不起作用我收到此错误：

Error: Trying to open unclosed connection.

不知道是不是因为是异步的

正如已经说过的，你可以使用useDb功能 ：

示例代码：

async function myDbConnection() {

    const url = 'mongodb+srv://username:[email protected]/test?retryWrites=true&w=majority';

    try {
        await mongoose.connect(url, { useNewUrlParser: true });
        console.log('Connected Successfully')
        // Here from above url you've already got connected to test DB,
           So let's make a switch as needed.
        mongoose.connection.useDb('myDB'); // Switching happens here..
        /**
         * Do some DB transaction with mongoose models as by now models has already been registered to created DB connection
         */
    } catch (error) {
        console.log('Error connecting to DB ::', error);
    }
}

或者，如果您想创建一个全新的连接，那么您必须尝试mongoose.createConnection()。仅供参考，以防万一mongoDB您将使用的驱动程序::

mongodb.MongoClient.connect(mongourl, function(err, primaryDB) {
  // open another database over the same connection
  const secondaryDB = primaryDB.db(SECONDARY_DATABASE_NAME);

  // now you can use both `database` and `database2`
  ...
});

Ref : 猫鼬多个不同的连接, 猫鼬 useDb(), mongoDB驱动程序切换连接