MongoDB在文档内移动元素

xytpbqjk 于 2023-01-04 发布在 Go

关注(0)|答案(2)|浏览(99)

我想更新所有与某个字段匹配的文档并移动此元素（并且我想保留此元素的所有属性）。
数据集：

[{
    "name": "Guillaume",
    "childrens": [{
        "name": "Robert",
        "degree": "License"
    }
    ],
    "students": [
    {
        "name": "Hélène",
        "degree": "License"
    }]
},
{
    "name": "Mathilde",
    "childrens": [ {
        "name": "Lucie",
        "degree": "License"
    }],
    "students": [
    {
        "name": "Michel",
        "degree": "License"
    }]
}]

For example, I would like to update "childrens.degree" = Master to all childrens that match name "Robert" and move this child to "students". Expected result :

[{
    "name": "Guillaume",
    "childrens": [],
    "students": [
    {
        "name": "Hélène",
        "degree": "License"
    },
    {
        "name": "Robert",
        "degree": "Master"
    }]
},
{
    "name": "Mathilde",
    "childrens": [
    {
        "name": "Lucie",
        "degree": "License"
    }],
    "students": [
    {
        "name": "Michel",
        "degree": "License"
    }]
}]

我更新了与Robert匹配的所有文档，但未能将子Robert移入学生

db.person.updateMany(
{"childrens.name": "Robert" },
{
        $set: {
            "childrens.$[child].degree": "Master"
        }
},
{ arrayFilters: [ {"child.name": "Robert"} ] }
)

我尝试了：

db.person.updateMany(
{"childrens.name": "Robert" },
{
        $set: {
            "childrens.$[child].degree": "Master",
            $push: {
                "students": "childrens.$[child]"
            }
        }
},
{ arrayFilters: [ {"child.name": "Robert"} ] }
)

mongodb

来源：https://stackoverflow.com/questions/74983576/mongodb-move-element-inside-a-document

2条答案

按热度按时间

zkure5ic1#

你想使用pipelined updates来完成这个任务，现在我们可以从所有的“roberts”中过滤出children数组，同时使用concatArrays将它们添加到students数组（同时也改变它们的学位），如下所示：

db.collection.updateMany(
{ "childrens.name": "Robert" },
[
  {
    $set: {
      childrens: {
        $filter: {
          input: {
            $ifNull: [
              "$childrens",
              []
            ]
          },
          cond: {
            $ne: [
              "$$this.name",
              "Robert"
            ]
          }
        }
      },
      students: {
        $concatArrays: [
          {
            $ifNull: [
              "$students",
              []
            ]
          },
          {
            $map: {
              input: {
                $filter: {
                  input: {
                    $ifNull: [
                      "$childrens",
                      []
                    ]
                  },
                  cond: {
                    $eq: [
                      "$$this.name",
                      "Robert"
                    ]
                  }
                }
              },
              in: {
                $mergeObjects: [
                  "$$this",
                  {
                    degree: "Master"
                  }
                ]
              }
            }
          }
        ]
      }
    }
  }
])

Mongo Playground

赞(0）回复(0）举报 2023-01-04

vhmi4jdf2#

db.person.updateMany(
{"childrens.name": "Robert"},
{
    $push: {
        "students": {"name": "Robert", "degree": "Masters"}
    },
    $pull: {
        "childrens": {"name": "Robert"}
    }
}
);

Playground

赞(0）回复(0）举报 2023-01-04

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MongoDB在文档内移动元素

2条答案

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