数据：
[
{
"_id" : ObjectId("597c48d222b29fc421e82d20"),
"Date" : "12/06/2017",
"Country" : "DEMO",
"RiderId" : "DEMO",
"VehicleId" : "DEMO",
"StartAddress" : "Colombo",
"StartLocation" : [
6.9270974,
79.8612478
],
"EndAddress" : "Kegalle,",
"EndLocation" : [
7.2476005,
80.3483415
],
"DepartureAddress" : "Dellogistics International (Pvt) Ltd, Colombo 04",
"DepartureLocation" : [
6.8824893,
79.8620031
],
"ArrivalAddress" : "Osro, Kegalle",
"ArrivalLocation" : [
7.2476005,
80.3483415
],
"IsLadiesOnly" : false,
"Notes" : "\"I'm travalleing from Bambalapitiya to Kegalle, small luggages are ok\"",
"Luggage" : 2.0,
"Detours" : 1.0,
"Route" : {
"Bounds" : {
"NorthEast" : [
7.2916216,
80.6341326
],
"SouthWest" : [
6.9270974,
79.8607731
]
},
"Legs" : [
{
"LegId" : 0.0,
"Distance" : 40033.0,
"Duration" : 4725.0,
"Price" : "240",
"StartAddress" : "Colombo",
"StartLocation" : [
6.9270974,
6.9270974
],
"EndAddress" : "Nittambuwa",
"EndLocation" : [
7.1420863,
80.1038061
],
"Ancestors" : []
},
{
"LegId" : 1.0,
"Distance" : 18008.0,
"Duration" : 1850.0,
"Price" : "480",
"StartAddress" : "Nittambuwa",
"StartLocation" : [
7.1420863,
80.1038061
],
"EndAddress" : "Warakapola",
"EndLocation" : [
7.2268383,
80.1959644
],
"Ancestors" : [
"Colombo"
]
},
{
"LegId" : 2.0,
"Distance" : 22478.0,
"Duration" : 2208.0,
"Price" : "720",
"StartAddress" : "Warakapola",
"StartLocation" : [
7.2268383,
80.1959644
],
"EndAddress" : "Kegalle",
"EndLocation" : [
7.2514362,
80.3466076
],
"Ancestors" : [
"Colombo",
"Nittambuwa"
]
}
]
},
"CreatedDate" : "2017-01-06T07:00:00.000Z",
"ModifiedDate" : "01/06/2017 12:30",
"Points" : "123"
}]
查询是：
db.trips.aggregate([
{$match: { "Route.Legs": { $elemMatch: { "StartAddress": "Nittambuwa","Ancestors":{$nin:["Kegalle"]}} }, "Route.Legs.EndAddress":"Kegalle" }},
{ $project: {
RiderId: "$RiderId",
Legs: {
$filter: {
input: "$Route.Legs",
as: "leg",
cond: {
"$and": [
{ "$gte": [ "$$leg.LegId", <**Get the leg id by passing the start address**> ] },
{ "$lte": [ "$$leg.LegId", 3 ] }
]
}
}
}
}}
])
基本在条件内我需要查询集合并获取腿部ID进行比较。我试过$ where但是它不能识别条件下的操作符。
另外，为什么我不能在cond中使用$ where，$ nin
答案 0 :(得分：2)
您通常需要通过在外部$filter内嵌套另一个$filter来应用条件，该$map查找匹配的数组条目并匹配条件。然后应用$arrayElemAt和$gte实际提供$indexOfArray条件的"LegId"值：
db.trips.aggregate([
{ "$match": {
"Route.Legs": {
"$elemMatch": {
"StartAddress": "Nittambuwa",
"Ancestors":{ "$nin": [ "Kegalle" ] }
}
},
"Route.Legs.EndAddress":"Kegalle"
}},
{ "$project": {
"RiderId": 1,
"Legs": {
"$filter": {
"input": "$Route.Legs",
"as": "l",
"cond": {
"$and": [
{ "$gte": [
"$$l.LegId",
{ "$arrayElemAt": [
{ "$map": {
"input": {
"$filter": {
"input": "$Route.Legs",
"as": "l",
"cond": {
"$and": [
{ "$eq": [ "$$l.StartAddress", "Nittambuwa" ] },
{ "$eq": [
{ "$size": {
"$setIntersection": [ [ "Kegalle" ], "$$l.Ancestors" ]
}},
0
]}
]
}
}
},
"as": "l",
"in": "$$l.LegId"
}},
0
]}
]},
{ "$lte": [ "$$l.LegId", 3 ] }
]
}
}
}
}}
])
由于＆＃34;多个条件＆＃34>，您无法真正在此处应用$nin这样的内容来获取数组索引。需要匹配数组元素。
虽然没有＆＃34;直接＆＃34;等同于$setIntersection作为＆＃34;逻辑运算符＆＃34;对于聚合条件，您可以使用替代方案。在这里，我申请$size，因为它可能是最好的比较两个＆＃34; unique＆＃34;阵列。逻辑说明当＆＃34;交叉路口的$nin＆＃34;是0，那里没有匹配。因此符合与$and相同的标准。
当然＆＃34;倍数＆＃34;条件都由RowData包裹，因为它就是它的作用。
结果当然会过滤匹配条件的"LegId"值与＆＃34; end＆＃34;之间的数组项。提供的值，即3：
/* 1 */
{
"_id" : ObjectId("597c48d222b29fc421e82d20"),
"RiderId" : "DEMO",
"Legs" : [
{
"LegId" : 1.0,
"Distance" : 18008.0,
"Duration" : 1850.0,
"Price" : "480",
"StartAddress" : "Nittambuwa",
"StartLocation" : [
7.1420863,
80.1038061
],
"EndAddress" : "Warakapola",
"EndLocation" : [
7.2268383,
80.1959644
],
"Ancestors" : [
"Colombo"
]
},
{
"LegId" : 2.0,
"Distance" : 22478.0,
"Duration" : 2208.0,
"Price" : "720",
"StartAddress" : "Warakapola",
"StartLocation" : [
7.2268383,
80.1959644
],
"EndAddress" : "Kegalle",
"EndLocation" : [
7.2514362,
80.3466076
],
"Ancestors" : [
"Colombo",
"Nittambuwa"
]
}
]
}
全部从提供的数据中复制和粘贴，并在此处发布声明的结果。