我正在尝试执行聚合函数,以基于名称值计算成本和利润率值的总和。因此,如果多个结果的名称为“假供应商”,则我需要成本结果和保证金结果的总和。
查询语句:
Pharmacy.aggregate([
{
$match: {
$and: [{ 'prescription.status': 'Ready for Pickup' }]
}
},
{
$project: {
'insurance.primary.name': 1,
'prescription.financial.cost': 1,
'prescription.financial.margin': 1
}
}
])
结果类似于:
[
{
"_id": "5cab98cd293bd54e94c40461",
"insurance": {
"primary": {
"name": "Fake Provider 1"
}
},
"prescription": [
{
"financial": {
"cost": "2.89",
"margin": "5.60"
}
},
{
"financial": {
"cost": "0.88",
"margin": "1.24"
}
}
]
},
{
"_id": "5cab98d0293bd54e94c40470",
"insurance": {
"primary": {
"name": "Fake Provider 1"
}
},
"prescription": [
{
"financial": {
"cost": "3.22",
"margin": "9.94"
}
},
{
"financial": {
"cost": "2.57",
"margin": "9.29"
}
},
{
"financial": {
"cost": "2.03",
"margin": "10.17"
}
}
]
}
]
我尝试创建一个没有任何运气的组语句。同样,成本和利润率值当前存储为字符串。
$group: {
_id: '$insurance.primary.name',
Financial: {
$push: {
id: '$insurance.primary.name',
name: '$insurance.primary.name',
cost: '$prescription.financial.cost',
margin: '$prescription.financial.margin'
}
}
}
我想得到类似以下结果:
[
{
"primaryInsurance": "Fake Provider 1",
"totalFinancialCost": "11.59",
"totalFinancialMargin": "36.24"
},
{
"primaryInsurance": "Fake Provider 2",
"totalFinancialCost": "12.82",
"totalFinancialMargin": "22.16"
}
]
我认为我有一个解决方案,该解决方案使用查找和投影返回结果,然后使用javascript通过结果映射并执行加法。但是,我宁愿在数据库级别执行此操作。
答案 0 :(得分:2)
您必须先展开“处方”字段,然后再进行分组。尝试以下管道:
let pipeline = [
{
$unwind: {
path: '$prescription'
}
},
{
$group: {
_id: '$insurance.primary.name',
totalFinancialCost: {
$sum: { $convert: { input: '$prescription.financial.cost', to: "decimal" } }
},
totalFinancialMargin: {
$sum: { $convert: { input: '$prescription.financial.margin', to: "decimal" } }
}
}
}]
请注意如何将这些值转换为十进制以便执行总和。