如何在mongoDB中的集合记录中对数组进行排序

您将需要在应用程序代码中或在MongoDB 2.2中使用新的Aggregationframework来操纵嵌入式数组。

mongo

db.students.aggregate(    // Initial document match (uses index, if a suitable one is available)    { $match: {        _id : 1    }},    // Expand the scores array into a stream of documents    { $unwind: '$scores' },    // Filter to 'homework' scores     { $match: {        'scores.type': 'homework'    }},    // Sort in descending order    { $sort: {        'scores.score': -1    }})

样本输出：

{    "result" : [        { "_id" : 1, "name" : "Aurelia Menendez", "scores" : {     "type" : "homework",     "score" : 71.76133439165544 }        },        { "_id" : 1, "name" : "Aurelia Menendez", "scores" : {     "type" : "homework",     "score" : 34.85718117893772 }        }    ],    "ok" : 1}