$group 和 $lookup 没有提供正确的数据答案

【问题标题】：$group and $lookup is not giving proper data$group 和 $lookup 没有提供正确的数据
【发布时间】：2021-10-26 08:22:34
【问题描述】：

我有这样的代码

const aggregate = [];
const lookup = {
  $lookup: {
    from: "balances",
    localField: "accountNumber",
    foreignField: "account_id",
    as: "bankbalance",
  },
};
const unwind = {
  $unwind: "$bankbalance",
};
const match = {
  $match: {
    "bankbalance.date": {
      $gte: startDate,
      $lte: endDate,
    },
    userId: mongoose.Types.ObjectId(userId),
    isActive: 1,
    type: "accountType"
  },
};
const group = {
  $group: {
    _id: '$_id',
    accountNumber:{"$first":"$accountNumber"},
    balances: {
      $addToSet: { date: "$$ROOT.date", amount: "$$ROOT.amount" },
    },
  },
};

aggregate.push(lookup);
aggregate.push(unwind);
aggregate.push(group);
aggregate.push(match);

let data = await BankAccounts.aggregate(aggregate);

这段代码给了我空的 [] 数据，如果我不使用 $group 那么它给我的数据是这样的

{
_id: 611bc2c4f9649b2c6fe4007f,
bankId: 'string',
mask: '0000',
name: 'Plaid Checking',
userId: 611bc2794d9f391bf2cd7877,
accountNumber: 'xxxxxxxxxxxxxxxxxxx',
bankTokenId: xxxxxxxxxxxxxxxxxxxxxxxxxxx,
createdAt: 2021-08-17T14:08:04.058Z,
isConnected: true,
subtype: 'checking',
type: 'depository',
updatedAt: 2021-08-25T11:36:37.824Z,
isActive: 1,
bankbalance: {
  _id: 61262b9bf9649b2c6fe7d67c,
  ISODate: '2021-05-19T00:00:00.000Z',
  account_id: 'xxxxxxxxxxxxxxxxxxxxxxxx',
  userId: 611bc2794d9f391bf2cd7877,
  ISOCountryCode: null,
  accountId: xxxxxxxxxxxxxxxxxxxx,
  amount: -1047.62,
  bankTokenId: xxxxxxxxxxxxxxxxxxxx,
  createdAt: 2021-08-25T11:37:26.960Z,
  current: null,
  date: '2021-05-19',
  institutionId: xxxxxxxxxxxxxxxxxxxxxx,
  isActive: 1,
  unofficialCountryCode: null,
  updatedAt: 2021-08-25T11:37:26.960Z
 }
},
{
_id: 611bc2c4f9649b2c6fe4007f,
bankId: 'string',
mask: '0000',
name: 'Plaid Checking',
userId: 611bc2794d9f391bf2cd7877,
accountNumber: 'xxxxxxxxxxxxxxxxxxx',
bankTokenId: xxxxxxxxxxxxxxxxxxxxxxxxxxx,
createdAt: 2021-08-17T14:08:04.058Z,
isConnected: true,
subtype: 'checking',
type: 'depository',
updatedAt: 2021-08-25T11:36:37.824Z,
isActive: 1,
bankbalance: {
  _id: 61262b99f9649b2c6fe7d671,
  ISODate: '2021-05-24T00:00:00.000Z',
  account_id: 'xxxxxxxxxxxxxxxxxxxxxxxx',
  userId: 611bc2794d9f391bf2cd7877,
  ISOCountryCode: null,
  accountId: xxxxxxxxxxxxxxxxxxxx,
  amount: -1137.02,
  bankTokenId: xxxxxxxxxxxxxxxxxxxx,
  createdAt: 2021-08-25T11:37:26.960Z,
  current: null,
  date: '2021-05-24',
  institutionId: xxxxxxxxxxxxxxxxxxxxxx,
  isActive: 1,
  unofficialCountryCode: null,
  updatedAt: 2021-08-25T11:37:26.960Z
 }
}

这是一次又一次地给出所有数据记录，这里2个集合之间的引用是accountNumber和account_id。我想将所有记录分组为 1 喜欢

{
_id: 611bc2c4f9649b2c6fe4007f,
bankId: 'string',
mask: '0000',
name: 'Plaid Checking',
userId: 611bc2794d9f391bf2cd7877,
accountNumber: 'xxxxxxxxxxxxxxxxxxx',
bankTokenId: xxxxxxxxxxxxxxxxxxxxxxxxxxx,
createdAt: 2021-08-17T14:08:04.058Z,
isConnected: true,
subtype: 'checking',
type: 'depository',
updatedAt: 2021-08-25T11:36:37.824Z,
isActive: 1,
bankbalance: [{
  _id: 61262b99f9649b2c6fe7d671,
  ISODate: '2021-05-24T00:00:00.000Z',
  account_id: 'xxxxxxxxxxxxxxxxxxxxxxxx',
  userId: 611bc2794d9f391bf2cd7877,
  ISOCountryCode: null,
  accountId: xxxxxxxxxxxxxxxxxxxx,
  amount: -1137.02,
  bankTokenId: xxxxxxxxxxxxxxxxxxxx,
  createdAt: 2021-08-25T11:37:26.960Z,
  current: null,
  date: '2021-05-24',
  institutionId: xxxxxxxxxxxxxxxxxxxxxx,
  isActive: 1,
  unofficialCountryCode: null,
  updatedAt: 2021-08-25T11:37:26.960Z
 },
 {
  _id: 61262b9bf9649b2c6fe7d67c,
  ISODate: '2021-05-19T00:00:00.000Z',
  account_id: 'xxxxxxxxxxxxxxxxxxxxxxxx',
  userId: 611bc2794d9f391bf2cd7877,
  ISOCountryCode: null,
  accountId: xxxxxxxxxxxxxxxxxxxx,
  amount: -1047.62,
  bankTokenId: xxxxxxxxxxxxxxxxxxxx,
  createdAt: 2021-08-25T11:37:26.960Z,
  current: null,
  date: '2021-05-19',
  institutionId: xxxxxxxxxxxxxxxxxxxxxx,
  isActive: 1,
  unofficialCountryCode: null,
  updatedAt: 2021-08-25T11:37:26.960Z
 }
]
}

还可以按日期对银行余额进行排序。任何帮助！提前致谢！！

【问题讨论】：

标签： mongodb mongoose aggregation-framework aggregation

【解决方案1】：

阶段是按顺序排列的

aggregate.push(lookup);
aggregate.push(unwind);
aggregate.push(group);
aggregate.push(match);

当小组阶段执行时，每个文档将仅包含该阶段中记录的字段。即

{
  _id: 611bc2c4f9649b2c6fe4007f,
  accountNumber: 'xxxxxxxxxxxxxxxxxxx',
  balances: [ {date: ......, amount: .....} ]
}

执行匹配阶段时，"bankbalance.date"、userId、isActive 和 type 字段不存在，因此没有满足匹配的文档。

【讨论】：

谢谢乔，但我使用的是相同的顺序。我需要将所有记录分组到余额下的一个记录中。无论我写什么都行不通。
您需要在分组之前进行匹配，或者将匹配阶段更改为仅检查分组后实际存在的字段。
谢谢乔，这很有效 const group = { $group: { _id: '$accountNumber', balances: { $addToSet: { date: "$bankbalance.date", amount: "$bankbalance.金额" }, }, }, };
在分组之前排序可能是最简单的。
const sort = { $sort: { "bankbalance.date": -1 } };我在小组之前使用过这个，但它不起作用