add 'group by' in aggregating

[huangyingjie]

Hello,
How can I use the words 'group by'? To achieve the effect like "select avg(weight), age from person group by age". Or is there any way by method find?

[dresende]

Using the git version (not npm), try this: (adjust to your needs)

Person.aggregate([ 'age' ]).avg('weight').groupBy('age').get(function (err, stats) {
    // stats is an Array, each item should have 'age' and 'avg_weight'
});