我正在进行MongoDB聚合。我想查找两个集合,然后只在嵌套数组中投影所需的字段。
要查找的两个集合:
db.pitcher.find()。漂亮()
{
"_id" : ObjectId("59b22eeef224252e6c7eeaf6"),
"userId" : "a0",
"name" : "test50000",
"index" : 50000,
"position" : "SP",
"order" : 0,
"gameRecord" : [
{
"seasonIndex" : 2017251,
"gameIndex" : 1,
"ERA" : 3.00,
},
{
"seasonIndex" : 2017251,
"gameIndex" : 2,
"ERA" : 4.50,
}
]
}
db.gameResult.find()。漂亮()
{
"_id" : ObjectId("59b22b7dac48252e6c7eeaf6"),
"seasonIndex" : 2017251,
"gameIndex" : 1,
"away" : "a9",
"home" : "a0",
"awayScore" : 9,
"homeScore" : 4,
"awayPitcherList" : [
50180
],
"homePitcherList" : [
50000,
50049,
50048,
50047
]
}
汇总查询:
> db.gameResult.aggregate([
{
$match : {gameIndex : 1 ,home : "a0"}
},
{
$lookup:
{
from: "pitcher",
localField : "awayPitcherList",
foreignField : "index",
as: "awayPitcherList"
}
},
{
$lookup:
{
from: "pitcher",
localField : "homePitcherList",
foreignField : "index",
as: "homePitcherList"
}
}
]).pretty()
最后期望输出:
"_id" : ObjectId("59b22b7dac48252e6c7eeaf6"),
"seasonIndex" : 2017251,
"gameIndex" : 1,
"away" : "a9",
"home" : "a0",
"awayScore" : 9,
"homeScore" : 4,
"awayPitcherList" : [
{
"name" : "test50180",
"gameRecord" : [
{
"seasonIndex" : 2017251,
"gameIndex" : 1,
"ERA" : 3.00,
}
]
],
"homePitcherList" : [
{
"name" : "test50000",
"gameRecord" : [
{
"seasonIndex" : 2017251,
"gameIndex" : 1,
"ERA" : 3.00,
}
],
{
"name" : "test50049",
"gameRecord" : [
{
"seasonIndex" : 2017251,
"gameIndex" : 1,
"ERA" : 3.00,
}
],
{
"name" : "test50048",
"gameRecord" : [
{
"seasonIndex" : 2017251,
"gameIndex" : 1,
"ERA" : 3.00,
}
],
{
"name" : "test50047",
"gameRecord" : [
{
"seasonIndex" : 2017251,
"gameIndex" : 1,
"ERA" : 3.00,
}
]
]
我想要名称和gameRecord,其中包含(在这种情况下)1的gameIndex。
请改进我的汇总查询。 如果你有一个,那么Spring代码有很多tnx。
答案 0 :(得分:4)
您可以在3.4。
中使用以下查询以下查询使用$addFields
覆盖现有的awayPitcherList
,其中包含awayPitcherList
和name
的更新gameRecord
。
$map
阶段保持name
字段和$filter
过滤gameRecord
以仅保留匹配的gameIndex
元素。
homePitcherList
的类似汇总。
db.gameResult.aggregate(
[
{
"$match": {
"gameIndex": 1,
"home": "a0"
}
},
{
"$lookup": {
"from": "pitcher",
"localField": "awayPitcherList",
"foreignField": "index",
"as": "awayPitcherList"
}
},
{
"$addFields": {
"awayPitcherList": {
"$map": {
"input": "$awayPitcherList",
"as": "awayPitcher",
"in": {
"name": "$$awayPitcher.name",
"gameRecord": {
"$filter": {
"input": "$$awayPitcher.gameRecord",
"as": "gameRecord",
"cond": {
"$eq": [
"$$gameRecord.gameIndex",
1
]
}
}
}
}
}
}
}
},
{
"$lookup": {
"from": "pitcher",
"localField": "homePitcherList",
"foreignField": "index",
"as": "homePitcherList"
}
},
{
"$addFields": {
"homePitcherList": {
"$map": {
"input": "$homePitcherList",
"as": "homePitcher",
"in": {
"name": "$$homePitcher.name",
"gameRecord": {
"$filter": {
"input": "$$homePitcher.gameRecord",
"as": "gameRecord",
"cond": {
"$eq": [
"$$gameRecord.gameIndex",
1
]
}
}
}
}
}
}
}
}
])
使用以下聚合查询3.2。
db.gameResult.aggregate(
[
{
"$match": {
"gameIndex": 1,
"home": "a0"
}
},
{
"$lookup": {
"from": "pitcher",
"localField": "awayPitcherList",
"foreignField": "index",
"as": "awayPitcherList"
}
},
{
"$project": {
"homePitcherList":1,
"awayPitcherList": {
"$map": {
"input": "$awayPitcherList",
"as": "awayPitcher",
"in": {
"name": "$$awayPitcher.name",
"gameRecord": {
"$filter": {
"input": "$$awayPitcher.gameRecord",
"as": "gameRecord",
"cond": {
"$eq": [
"$$gameRecord.gameIndex",
1
]
}
}
}
}
}
}
}
},
{
"$lookup": {
"from": "pitcher",
"localField": "homePitcherList",
"foreignField": "index",
"as": "homePitcherList"
}
},
{
"$project": {
"awayPitcherList":1,
"homePitcherList": {
"$map": {
"input": "$homePitcherList",
"as": "homePitcher",
"in": {
"name": "$$homePitcher.name",
"gameRecord": {
"$filter": {
"input": "$$homePitcher.gameRecord",
"as": "gameRecord",
"cond": {
"$eq": [
"$$gameRecord.gameIndex",
1
]
}
}
}
}
}
}
}
}
])