I receive a large amount of JSON back (flight data) which I've been thinking about using mongo as the tool to query/filter it before returning back to the UI.
Here's the json response from Sabre (flight search)
{
"OTA_AirLowFareSearchRS": {
"PricedItineraries": {
"PricedItinerary": [
{
"SequenceNumber": 1,
"AirItinerary": {
"OriginDestinationOptions": {
"OriginDestinationOption": [
{
"FlightSegment": [
{
"DepartureDateTime": "2015-11-12T11:40:00",
"ArrivalDateTime": "2015-11-12T17:35:00",
"FlightNumber": "1980"
},
{
"DepartureDateTime": "2015-11-12T19:35:00",
"ArrivalDateTime": "2015-11-13T02:00:00",
"FlightNumber": "760"
}
]
},
{
"FlightSegment": [
{
"DepartureDateTime": "2015-11-19T08:25:00",
"ArrivalDateTime": "2015-11-19T11:40:00",
"FlightNumber": "763"
},
{
"DepartureDateTime": "2015-11-19T12:55:00",
"ArrivalDateTime": "2015-11-19T15:05:00",
"FlightNumber": "1985"
}
]
}
]
}
},
"AirItineraryPricingInfo": [
{
"ItinTotalFare": {
"TotalFare": {
"Amount": 269.56,
"CurrencyCode": "GBP"
}
}
}
]
},
{
"SequenceNumber": 2,
"AirItinerary": {
"OriginDestinationOptions": {
"OriginDestinationOption": [
{
"FlightSegment": [
{
"DepartureDateTime": "2015-11-12T16:45:00",
"ArrivalDateTime": "2015-11-12T22:40:00",
"FlightNumber": "1986"
},
{
"DepartureDateTime": "2015-11-13T00:40:00",
"ArrivalDateTime": "2015-11-13T07:10:00",
"FlightNumber": "762"
}
]
},
{
"ElapsedTime": 640,
"FlightSegment": [
{
"DepartureDateTime": "2015-11-19T08:25:00",
"ArrivalDateTime": "2015-11-19T11:40:00",
"FlightNumber": "763"
},
{
"DepartureDateTime": "2015-11-19T12:55:00",
"ArrivalDateTime": "2015-11-19T15:05:00",
"FlightNumber": "1985"
}
]
}
]
}
},
"AirItineraryPricingInfo": [
{
"ItinTotalFare": {
"TotalFare": {
"Amount": 269.56,
"CurrencyCode": "GBP"
}
}
}
]
},
{
"SequenceNumber": 6,
"AirItinerary": {
"OriginDestinationOptions": {
"OriginDestinationOption": [
{
"FlightSegment": [
{
"DepartureDateTime": "2015-11-12T11:40:00",
"ArrivalDateTime": "2015-11-12T17:35:00",
"FlightNumber": "1980"
},
{
"DepartureDateTime": "2015-11-12T19:35:00",
"ArrivalDateTime": "2015-11-13T02:00:00",
"FlightNumber": "760"
}
]
},
{
"FlightSegment": [
{
"DepartureDateTime": "2015-11-19T03:15:00",
"ArrivalDateTime": "2015-11-19T06:30:00",
"FlightNumber": "761"
},
{
"DepartureDateTime": "2015-11-19T12:55:00",
"ArrivalDateTime": "2015-11-19T15:05:00",
"FlightNumber": "1985"
}
]
}
]
}
},
"AirItineraryPricingInfo": [
{
"ItinTotalFare": {
"TotalFare": {
"Amount": 269.56
}
}
}
]
}
]
}
}
}
I've been trying to get this into a view that I want but struggling with the complexity of all the nested arrays. My question is how can I achieve a desired result like this:
{
'Price': 269.56, <-- //Group on price (TotalFare)
'Outbound': [{
<Outbound Flights> <--- //$push? flights at array position [0] of OriginDestinationOption
}],
'Inbound': [{
<Inbound Flights> <-- // flights at array position [1] of OriginDestinationOption
}]
},
...
The locations of the data for these in the JSON is:
Price: OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary[x].AirItineraryPricingInfo[0].ItinTotalFare.TotalFare.Amount;
Inbound: OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary[x].AirItinerary.OriginDestinationOptions.OriginDestinationOption[0]
Outbound: OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary[x].AirItinerary.OriginDestinationOptions.OriginDestinationOption[1]
With the current MongoDB release, the only way you can get results which are closer to what you want is by using the aggregation framework, and working on the premise that the OriginDestinationOption array will have two elememts, you'd need the $first and $last operators to select the first and last elements in the array after the $unwind operator. For now (based on the above assumptions) you may have to do with running this pipeline:
db.flights.aggregate([
{ "$unwind": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary" },
{ "$unwind": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary.AirItineraryPricingInfo" },
{ "$unwind": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary.AirItinerary.OriginDestinationOptions.OriginDestinationOption" },
{
"$project": {
"Price": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary.AirItineraryPricingInfo.ItinTotalFare.TotalFare.Amount",
"DestinationOptions": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary.AirItinerary.OriginDestinationOptions.OriginDestinationOption"
}
},
{
"$group": {
"_id": "$Price",
"Outbound" : { "$first": "$DestinationOptions" },
"Inbound" : { "$last": "$DestinationOptions" }
}
}
])
which will yield the result (from the sample data):
/* 1 */
{
"result" : [
{
"_id" : 269.56,
"Outbound" : {
"ElapsedTime" : 620,
"FlightSegment" : [
{
"DepartureDateTime" : "2015-11-12T11:40:00",
"ArrivalDateTime" : "2015-11-12T17:35:00",
"StopQuantity" : 0,
"FlightNumber" : "1980",
"ElapsedTime" : 235,
"DepartureAirport" : {
"LocationCode" : "LHR",
"TerminalID" : "2",
"content" : ""
},
"ArrivalAirport" : {
"LocationCode" : "IST",
"TerminalID" : "I",
"content" : ""
},
"OperatingAirline" : {
"Code" : "TK",
"FlightNumber" : "1980",
"content" : ""
}
},
{
"DepartureDateTime" : "2015-11-12T19:35:00",
"ArrivalDateTime" : "2015-11-13T02:00:00",
"StopQuantity" : 0,
"FlightNumber" : "760",
"ResBookDesigCode" : "W",
"ElapsedTime" : 265,
"DepartureAirport" : {
"LocationCode" : "IST",
"TerminalID" : "I",
"content" : ""
},
"ArrivalAirport" : {
"LocationCode" : "DXB",
"TerminalID" : "1",
"content" : ""
},
"OperatingAirline" : {
"Code" : "TK",
"FlightNumber" : "760",
"content" : ""
},
"Equipment" : [
{
"AirEquipType" : "343",
"content" : ""
}
],
"MarketingAirline" : {
"Code" : "TK",
"content" : ""
},
"MarriageGrp" : "I",
"DepartureTimeZone" : {
"GMTOffset" : 2
},
"ArrivalTimeZone" : {
"GMTOffset" : 4
},
"TPA_Extensions" : {
"eTicket" : {
"Ind" : true
}
}
}
]
},
"Inbound" : {
"ElapsedTime" : 730,
"FlightSegment" : [
{
"DepartureDateTime" : "2015-11-19T08:25:00",
"ArrivalDateTime" : "2015-11-19T11:40:00",
"StopQuantity" : 0,
"FlightNumber" : "763",
"ResBookDesigCode" : "W",
"ElapsedTime" : 315,
"DepartureAirport" : {
"LocationCode" : "DXB",
"TerminalID" : "1",
"content" : ""
},
"ArrivalAirport" : {
"LocationCode" : "IST",
"TerminalID" : "I",
"content" : ""
},
"OperatingAirline" : {
"Code" : "TK",
"FlightNumber" : "763",
"content" : ""
},
"Equipment" : [
{
"AirEquipType" : "330",
"content" : ""
}
],
"MarketingAirline" : {
"Code" : "TK",
"content" : ""
},
"MarriageGrp" : "O",
"DepartureTimeZone" : {
"GMTOffset" : 4
},
"ArrivalTimeZone" : {
"GMTOffset" : 2
},
"TPA_Extensions" : {
"eTicket" : {
"Ind" : true
}
}
},
{
"DepartureDateTime" : "2015-11-19T14:25:00",
"ArrivalDateTime" : "2015-11-19T16:35:00",
"StopQuantity" : 0,
"FlightNumber" : "1971",
"ResBookDesigCode" : "W",
"ElapsedTime" : 250,
"DepartureAirport" : {
"LocationCode" : "IST",
"TerminalID" : "I",
"content" : ""
},
"ArrivalAirport" : {
"LocationCode" : "LHR",
"TerminalID" : "2",
"content" : ""
},
"OperatingAirline" : {
"Code" : "TK",
"FlightNumber" : "1971",
"content" : ""
},
"Equipment" : [
{
"AirEquipType" : "32B",
"content" : ""
}
],
"MarketingAirline" : {
"Code" : "TK",
"content" : ""
},
"MarriageGrp" : "I",
"DepartureTimeZone" : {
"GMTOffset" : 2
},
"ArrivalTimeZone" : {
"GMTOffset" : 0
},
"TPA_Extensions" : {
"eTicket" : {
"Ind" : true
}
}
}
]
}
}
],
"ok" : 1
}
However, with the future releases (MongoDB 3.2 and newer), there are two operators $slice and $arrayElemAt which will work for you to produce the desired result. The $slice operator returns a subset of an array and the $arrayElemAt returns the element at the specified array index.
Thus you will implement the pipeline as follows -
Case 1. Using the $slice operator:
db.flights.aggregate([
{ "$unwind": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary" },
{ "$unwind": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary.AirItineraryPricingInfo" },
{ "$unwind": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary.AirItinerary.OriginDestinationOptions.OriginDestinationOption" },
{
"$project": {
"Price": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary.AirItineraryPricingInfo.ItinTotalFare.TotalFare.Amount",
"DestinationOptions": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary.AirItinerary.OriginDestinationOptions.OriginDestinationOption"
}
},
{
"$group": {
"_id": "$Price",
"DestinationOptions" : { "$push": "$DestinationOptions" }
}
},
{
"$project": {
"Inbound": { "$slice": [ "$DestinationOptions", 0, 1] },
"Outbound": { "$slice": [ "$DestinationOptions", 1, 1 ] },
"Price": "$_id",
"_id": 0
}
}
])
Case 2. Using the $arrayElemAt operator:
db.flights.aggregate([
{ "$unwind": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary" },
{ "$unwind": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary.AirItineraryPricingInfo" },
{ "$unwind": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary.AirItinerary.OriginDestinationOptions.OriginDestinationOption" },
{
"$project": {
"Price": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary.AirItineraryPricingInfo.ItinTotalFare.TotalFare.Amount",
"DestinationOptions": "$OTA_AirLowFareSearchRS.PricedItineraries.PricedItinerary.AirItinerary.OriginDestinationOptions.OriginDestinationOption"
}
},
{
"$group": {
"_id": "$Price",
"DestinationOptions" : { "$push": "$DestinationOptions" }
}
},
{
"$project": {
"Inbound": { "$arrayElemAt": [ "$DestinationOptions", 0] },
"Outbound": { "$arrayElemAt": [ "$DestinationOptions", 1 ] },
"Price": "$_id",
"_id": 0
}
}
])