使用承諾。
var mongoose = require('mongoose');
mongoose.connect('your MongoDB connection string');
var conn = mongoose.connection;
var promises = ['aaa', 'bbb', 'ccc'].map(function(name) {
return new Promise(function(resolve, reject) {
var collection = conn.collection(name);
collection.drop(function(err) {
if (err) { return reject(err); }
console.log('dropped ' + name);
resolve();
});
});
});
Promise.all(promises)
.then(function() { console.log('all dropped)'); })
.catch(console.error);
這將丟棄每個集合，在每個集合之后打印“已刪除”，然后在完成時打印“全部刪除”。如果發(fā)生錯誤，則顯示為stderr。
先前的答案（這早于Node對Promises的本地支持）：
使用Q承諾或Bluebird承諾。
與Q：
var Q = require('q');
var mongoose = require('mongoose');
mongoose.connect('your MongoDB connection string');
var conn = mongoose.connection;
var promises = ['aaa','bbb','ccc'].map(function(name){
var collection = conn.collection(name);
return Q.ninvoke(collection, 'drop')
.then(function() { console.log('dropped ' + name); });
});
Q.all(promises)
.then(function() { console.log('all dropped'); })
.fail(console.error);
與藍鳥：
var Promise = require('bluebird');
var mongoose = Promise.promisifyAll(require('mongoose'));
mongoose.connect('your MongoDB connection string');
var conn = mongoose.connection;
var promises = ['aaa', 'bbb', 'ccc'].map(function(name) {
return conn.collection(name).dropAsync().then(function() {
console.log('dropped ' + name);
});
});
Promise.all(promises)
.then(function() { console.log('all dropped'); })
.error(console.error);
