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How can I upsert elements into an array of objects in MongoDB in a single update?

Lets say I have records like:

{
    "title": "something",
    "tags": [
        {
            "name": "tag1",
            "value": "something"
        },
        {
            "name": "tag2",
            "value": "anything"
        },
        {
            "name": "tag3",
            "value": "whatever"
        }
    ]
}

I want to update tags based on tags.name. I know I can use arrayFilters. However, what if I wish to bulk update multiple records of objects in the array? Suppose I want to "upsert" 2 tags

[
    { 
        "name": "tag2", 
        "value": "updated" 
    },
    { 
        "name": "tag-new", 
        "value": "new tag" 
    }
]

Can I do this merge in one operation such that I get something like:

{
    "title": "something",
    "tags": [
        {
            "name": "tag1",
            "value": "something"
        },
        {
            "name": "tag2",
            "value": "updated"
        },
        {
            "name": "tag3",
            "value": "whatever"
        },
        {
            "name": "tag-new",
            "value": "new tag"
        }
    ]
}

How can I acheive this is the best way?

Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    Managed to achive that using

    const upsertTags = [
    {
        "name": "t2",
        "v": "updated"
    },
    {
        "name": "tag-new",
        "v": "new tag"
    }
]

db.test.updateOne({
    title: "xyz"
}, [
    {
        $set: {
            tags: {
                $map: {
                    input: "$tags",
                    in: {
                        $mergeObjects: [
                            "$$this",
                            {
                                $switch: {
                                    branches: upsertTags.map(upsertTag => ({
                                        case: { $eq: ["$$this.name", upsertTag.name] },
                                        then: upsertTag
                                    })),
                                    default: {}
                                }
                            }
                        ]
                    }
                }
            }
        },
    },
    // Upsert tags that are not in the original array
    {
        $set: {
            tags: {
                $concatArrays: [
                    "$tags",
                    {
                        $map: {
                            input: {
                                $filter: {
                                    input: upsertTags,
                                    as: "tag",
                                    cond: {
                                        $not: {
                                            $in: ["$$tag.name", "$tags.name"]
                                        }
                                    }
                                }
                            },
                            in: "$$this"
                        }
                    }
                ]
            }
        },
    },
])

  2. 0

    You can use the $set and $addToSet operators with a combination of the arrayFilters option to update existing tags and add new ones. However, the challenge here is updating existing tags (name: tag2) and adding new tags (name: tag-new) in a single update operation.

    Query:

    db.collection.update(
  { "title": "something" }, // Filter the document
  [
    {
      $set: {
        // Update existing tags by finding matching tag name
        tags: {
          $map: {
            input: "$tags",
            as: "tag",
            in: {
              $cond: [
                { $eq: ["$$tag.name", "tag2"] },  // Condition to match tag by name
                { name: "$$tag.name", value: "updated" },  // Update tag2's value
                "$$tag"  // Keep other tags unchanged
              ]
            }
          }
        }
      }
    },
    {
      $addToSet: {
        // Add new tag if not already present
        tags: { name: "tag-new", value: "new tag" }
      }
    }
  ]
)

    $map is used to iterate over the tags array. It checks if the tag’s name matches tag2 and updates its value. Otherwise, the tag remains unchanged.
    $addToSet adds the new tag (tag-new) to the array only if it doesn’t exist.

    hope its work…

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