Question

使用NodeJS，MongoDb。

MongoClient返回一个非常好的承诺，但我不确定我是否正确使用它。做什么最干净的方法是什么：

const mongo = require('mongodb').MongoClient;
return mongo
         .connect(getConnectionString())
         .then(con => {
              func1(con)
              .then(val => {return func2(con, val);})
              .then(val => {con.close(); return val;})
              .catch(err => log.error(err));
          });

 //contrived func to get my point across
 func1(connection) {
     //use connection to fetch data
     return fetchedData;         
 }

 //contrived func to get my point across
 func2(connection, val) {
     //use connection to fetch data
     return fetchedData + val;         
 }

你看我是如何为连接创建一个范围的，这样我就可以用func1＆amp; amp;来关闭它。 func2完成了。有更清洁的方法吗？

如果有更简洁的方式来调用func1＆amp; funct2我也很感激。

Answer 1

我会使用Bluebird的.using

直接来自其API文档的示例

using(getConnection(), function(connection) {
   // Don't leak the `connection` variable anywhere from here
   // it is only guaranteed to be open while the promise returned from
   // this callback is still pending
   return connection.queryAsync("SELECT * FROM TABLE");
   // Code that is chained from the promise created in the line above
   // still has access to `connection`
}).then(function(rows) {
    // The connection has been closed by now
    console.log(rows);
});

在javascript中关闭承诺连接的最简洁方法是什么？

1 个答案: