我有一个 mongodb 集合数据,如下所示;我想按 EmployeedID(即 0001)分组,然后排序(按年龄)
{
"_id" : ObjectId("54d0512191a4da7736e9db43"),
"EmployeeID" : "0001",
"Speciality" : "xxx",
"Code" : "P",
"Age" : 8
}
/* 1 */
{
"_id" : ObjectId("54d0512191a4da7736e9db44"),
"EmployeeID" : "0002",
"Speciality" : "yyyyy",
"Code" : "P",
"Age" : 6
}
/* 2 */
{
"_id" : ObjectId("54d0512191a4da7736e9db45"),
"EmployeeID" : "0001",
"Speciality" : "zzz",
"Code" : "P",
"Age" : 5
}
我知道我可以使用以下方式进行分组。
collection.aggregate([
{$match:{"EmployeeId":0001}},
{$group:{"_id":"$EmployeeID",
"speciality":{$push:"$Speciality"},
"Code":{$push:"$Code"},
"Age":{$push:"$Age"}}}
])
但是我如何在这里使用 $sort 呢?所以我的结果可能如下所示;
[{ "EmployeeID" : "0001",
"speciality" : [ "zzz","xxx"],
"Code" :[ "P","P"],
"Age" : [5,8]
}]
最佳答案
您可以在分组阶段之前对文档进行排序:
collection.aggregate([
{$sort: {_id: -1}},
{$match:{"EmployeeId":0001}},
{$group:{"_id":"$EmployeeID",
"speciality":{$push:"$Speciality"},
"Code":{$push:"$Code"},
"Age":{$push:"$Age"}}}
])
关于node.js - Mongo : Group, 推送并排序,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/28301746/