Question

如何用mongoose实现分组计算的功能

Answer 1

用aggregate有一个问题，用$match无法匹配ObjectId
OutdoorApply.aggregate(
[
{$match : {mobile:'18988889991'}} //这样可以，因为mobile字段是字符串
{$match : {outdoorid:'5463fda5b0687cad05c3c7c0'}} //这样就无法匹配 ，因为outdoorid是ObjectId
// {$group:{ _id: {'outdoorid':'$outdoorid'}, count: { $sum: 1 }}}
],
function (err, res) {
if (err){
console.log('outdoorDao.getOutdoorApplyCount Error'+err);
return callback(err,null);
}
return callback(err,res);
}
);