Question

mongodb同时实现分组和分页

Answer 1

参考代码：
var pipeline =[
{
$match: {
sjbh: {$gte: beginDate, $lte:endDate}
}
},
{
$group: {
_id: "$gsbh",
totaltxl: {$sum: { $cond: { if: { $ne: [ "$totalnum","" ] }, then:"$txl" , else: 0 }}},
totalbmynum: {$sum: "$bmynum"}
}
},
{
$project: {
_id: 0,
gsbh: "$_id",
totaltxl: "$totaltxl",
totalbmynum: "$totalbmynum",
ratio: { $divide: [ "$totalbmynum", { $cond:{if: { $eq: [ "$totaltxl",0 ] }, then:1 , else: "$totaltxl" }}] }
}
},
{$sort: {ratio: -1}},
{$limit: 5}
{$skip : 5}
]

opts.dbs.csdb.collection("permydfx").aggregate(pipeline).......

Answer 2

分页使用skip就可以了，分组需要group分。