Essayez d'exécuter le pipeline d'agrégation suivant, la clé utilise un dernier $project
pipeline pour créer le attendeeContainer
sous-document :
db.event.aggregate([
{ "$unwind": "$attendeeContainer.attendees" },
{
"$lookup" : {
"from" : "contactinfo",
"localField" : "attendeeContainer.attendees.contact",
"foreignField" : "_id",
"as" : "attendeeContainer.attendees.contactInfo"
}
},
{ "$unwind": "$attendeeContainer.attendees.contactInfo" },
{
"$group": {
"_id" : "$_id",
"name": { "$first": "$name" },
"min" : { "$first": "$attendeeContainer.min" },
"max" : { "$first": "$attendeeContainer.max" },
"attendees": { "$push": "$attendeeContainer.attendees" }
}
},
{
"$project": {
"name": 1,
"attendeeContainer.min": "$min",
"attendeeContainer.max": "$min",
"attendeeContainer.attendees": "$attendees"
}
}
])
Conseils de débogage
En déboguant le pipeline à la 4ème étape, vous obtiendriez le résultat
db.event.aggregate([
{ "$unwind": "$attendeeContainer.attendees" },
{
"$lookup" : {
"from" : "contactinfo",
"localField" : "attendeeContainer.attendees.contact",
"foreignField" : "_id",
"as" : "attendeeContainer.attendees.contactInfo"
}
},
{ "$unwind": "$attendeeContainer.attendees.contactInfo" },
{
"$group": {
"_id": "$_id",
"name": { "$first": "$name" },
"min" : { "$first": "$attendeeContainer.min" },
"max" : { "$first": "$attendeeContainer.max" },
"attendees": { "$push": "$attendeeContainer.attendees" }
}
}/*,
{
"$project": {
"name": 1,
"attendeeContainer.min": "$min",
"attendeeContainer.max": "$min",
"attendeeContainer.attendees": "$attendees"
}
}*/
])
Résultat du pipeline
{
"_id" : ObjectId("582c789282a9183adc0b53f5"),
"name" : "Some Event",
"min" : 0,
"max" : 10,
"attendees" : [
{
"type" : 1,
"status" : 2,
"contact" : ObjectId("582c787682a9183adc0b53f3"),
"contactInfo" : {
"_id" : ObjectId("582c787682a9183adc0b53f3"),
"name" : "John Doe",
"age" : 35
}
},
{
"type" : 7,
"status" : 4,
"contact" : ObjectId("582c787682a9183adc0b53f4"),
"contactInfo" : {
"_id" : ObjectId("582c787682a9183adc0b53f4"),
"name" : "Peter Pan",
"age" : 60
}
}
]
}
et le dernier $project
pipeline vous donnera le résultat souhaité :
db.event.aggregate([
{ "$unwind": "$attendeeContainer.attendees" },
{
"$lookup" : {
"from" : "contactinfo",
"localField" : "attendeeContainer.attendees.contact",
"foreignField" : "_id",
"as" : "attendeeContainer.attendees.contactInfo"
}
},
{ "$unwind": "$attendeeContainer.attendees.contactInfo" },
{
"$group": {
"_id": "$_id",
"name": { "$first": "$name" },
"min" : { "$first": "$attendeeContainer.min" },
"max" : { "$first": "$attendeeContainer.max" },
"attendees": { "$push": "$attendeeContainer.attendees" }
}
},
{
"$project": {
"name": 1,
"attendeeContainer.min": "$min",
"attendeeContainer.max": "$min",
"attendeeContainer.attendees": "$attendees"
}
}/**/
])
Sortie souhaitée/réelle
{
"_id" : ObjectId("582c789282a9183adc0b53f5"),
"name" : "Some Event",
"attendeeContainer" : {
"min" : 0,
"max" : 10,
"attendees" : [
{
"type" : 1,
"status" : 2,
"contact" : ObjectId("582c787682a9183adc0b53f3"),
"contactInfo" : {
"_id" : ObjectId("582c787682a9183adc0b53f3"),
"name" : "John Doe",
"age" : 35
}
},
{
"type" : 7,
"status" : 4,
"contact" : ObjectId("582c787682a9183adc0b53f4"),
"contactInfo" : {
"_id" : ObjectId("582c787682a9183adc0b53f4"),
"name" : "Peter Pan",
"age" : 60
}
}
]
}
}