如何使用Waterline和Sails.js(版本0.10)从mongo数据库中提取不同的值?

Using Sails.js version 0.10.x, assume I have a model Dog, populated as follows (writtenout in yaml format for convenience, but in my case it's actually in a mongo database.)dogs:- breed: "wolf" name: "Fido"- breed: "wolf" name: "Roger"- breed: "dingo" name: "Nipper"- breed: "dingo" name: "Ernie"- breed: "corgi" name: "Bernadi"- breed: "corgi" name: "Queenie"- breed: "poodle" name: "Christopher"- breed: "poodle" name: "Tony"etc所以现在我要创建可用品种的列表.So now I want to create a list of the available breeds.Dog.find().exec(err, dogs) { breeds = []; dogs.each(function(dog)) { if (breeds.indexOf(dog.breed) === -1) breeds.push(dog.breed); } ...}是否有更简单的方法来减少数据库的点击次数?像Is there a simpler way to do this with fewer hits on the database? Something likeDog.find().distinct('breed').exec(function(err, breeds){ ...});我发现了这个封闭的水线问题，这似乎表明我可以使用.distinct方法，但我尝试过，可惜没有骰子.I've found this closed Waterline issue which seems to indicate that I could use a .distinct method but I tried it and alas no dice.Object [object Object] has no method 'distinct'我该如何以数据库有效的方式解决这个问题?How might I go about this in a database efficient manner?推荐答案对于这类查询，您可以使用native方法执行原始的MongoDB命令:For these kind of queries you can use use native method to execute raw MongoDB command:Dog.native(function(err, collection) { collection.distinct('breed', function(err, dogs) { // do something here });}); 这篇关于如何使用Waterline和Sails.js(版本0.10)从mongo数据库中提取不同的值?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！