教程示例的结果不正确,请官方修正
官方文档错误 https://developers.weixin.qq.com/miniprogram/dev/wxcloud/reference-sdk-api/database/aggregate/Aggregate.group.html avatar 集合 {
_id: "1",
alias: "john",
region: "asia",
scores: [40, 20, 80],
coins: 100
}
{
_id: "2",
alias: "arthur",
region: "europe",
scores: [60, 90],
coins: 20
}
{
_id: "3",
alias: "george",
region: "europe",
scores: [50, 70, 90],
coins: 50
}
{
_id: "4",
alias: "john",
region: "asia",
scores: [30, 60, 100, 90],
coins: 40
}
{
_id: "5",
alias: "george",
region: "europe",
scores: [20],
coins: 60
}
{
_id: "6",
alias: "john",
region: "asia",
scores: [40, 80, 70],
coins: 120
}
按多值分组 const $ = db.command.aggregate
db.collection('avatar').aggregate()
.group({
_id: {
region: '$region',
maxScore: $.max('$scores')
},
totalCoins: $.sum('$coins')
})
.end()
{
"_id": {
"region": "asia",
"maxScore": 80
},
"totalCoins": 220
}
{
"_id": {
"region": "asia",
"maxScore": 100
},
"totalCoins": 100 ****************************这里结果是错误的,应该是40************************
}
{
"_id": {
"region": "europe",
"maxScore": 90
},
"totalCoins": 70
}
{
"_id": {
"region": "europe",
"maxScore": 20
},
"totalCoins": 60
}