MongoDB/Pymongo：UpSert阵列元件

Question

我有以下文档：

    {'software_house': 'k1',
     'client_id': '1234',

     'transactions': [
      {'antecedents': 12345,
       'consequents': '015896018',
       'antecedent support': 0.0030889166727954697},

      {'antecedents': '932696735',
       'consequents': '939605046',
       'antecedent support': 0.0012502757961314996}
      ...
                     ]}

每个项目中的键“交易”存储在数组3个功能中。

我想更新“交易”数组中包含的每个项目，这些项目与相同的“ software_house”，“ client_id”，“ transactions.antecedents”和“ transactions.constequents”匹配；因此：

• 如果数组中的元素确实存在，则覆盖元素
• 在“交易”中附上一个新值，如果我该

如何使用pymongo实现这一目标？

Answer 1

您可以使用Contregation Pipeline进行更新来执行此操作。您可以首先 $ filter 匹配元素。然后 $ setunion 带有您要upsert

pymongo的项目：

db.collection.update_many(filter = {
  // the criteria you want to match outside array
  "software_house": "k1",
  "client_id": "1234"
},
update = [
  {
    "$addFields": {
      "transactions": {
        "$filter": {
          "input": "$transactions",
          "as": "t",
          "cond": {
            $not: {
              $and: [
                // the criteria you want to match in array
                {
                  $eq: [
                    "$t.antecedents",
                    12345
                  ]
                },
                {
                  $eq: [
                    "$t.consequents",
                    "015896018"
                  ]
                }
              ]
            }
          }
        }
      }
    }
  },
  {
    "$addFields": {
      "transactions": {
        "$setUnion": [
          "$transactions",
          [
            {
              "antecedents": 12345,
              "consequents": "the entry you want to upsert",
              "antecedent support": -1
            }
          ]
        ]
      }
    }
  }
])

本机mongodb查询：

db.collection.update({
  // the criteria you want to match outside array
  "software_house": "k1",
  "client_id": "1234"
},
[
  {
    "$addFields": {
      "transactions": {
        "$filter": {
          "input": "$transactions",
          "as": "t",
          "cond": {
            $not: {
              $and: [
                // the criteria you want to match in array
                {
                  $eq: [
                    "$t.antecedents",
                    12345
                  ]
                },
                {
                  $eq: [
                    "$t.consequents",
                    "015896018"
                  ]
                }
              ]
            }
          }
        }
      }
    }
  },
  {
    "$addFields": {
      "transactions": {
        "$setUnion": [
          "$transactions",
          [
            {
              "antecedents": 12345,
              "consequents": "the entry you want to upsert",
              "antecedent support": -1
            }
          ]
        ]
      }
    }
  }
],
{
  multi: true
})

这是供您参考。