猫鼬如何过滤文档中的objectIds数组

Question

如何在 mongo 文档中过滤对象 ID 的“数组”，使其不包含“60ba4ca6f170dsfa234”，并且将更新文档。谢谢！

{
    "_id" : ObjectId("60bfdae011abd61c3eec"),
    "array" : [ 
        ObjectId("60ba4ca6f170dsfa234"), 
        ObjectId("60bd240df30ead9293d")

}

Answer 1

您可以通过 $project 选项使用 $filter 管道阶段。

db.collection.aggregate([
  {
    "$project": {
      "array": {
        "$filter": {
          "input": "$array",
          "cond": {
            "$ne": [
              "$$this",
              {  // <-- Ignore this block and pass value directly you are passing `ObjectId` directly drom driver and conversion from string is not required
                "$toObjectId": "60407d54a8204c86a62bf231"  // <-- ObjectId you want to be removed from the array
              }
            ],
          },
        }
      },
    },
  },
  {
    "$merge": {
      "into": "collection",  // <-- Change to source collection name where the changes has to be updated
      "on": "_id",
      "whenMatched": "merge",
    },
  },
])

Mongo Playground Sample Execution