从嵌套文档数组 mongodb 更新特定元素，其中有两个匹配项 [英] update specific element from nested document array mongodb where has two matches

问题描述

如果不存在，我需要更新或创建特定对象，设置 score.b1 =50 和 total=100，其中对象匹配 curse=5 block=2

{ "_id":"sad445";年":2020，等级":4，部分":A"，id":100，名称":佩德罗"，注释":[{诅咒":5，块":1，分数":{ a1":5，a2":10，a3":15}，总": 50},{诅咒":5，块":2，分数":{ b1":10，b2":20，b3":30}，总": 20}]}

我可以更新所有 obj，但我需要更新或从分数中创建特定元素，而不是全部.和/或创建对象notes":[{curse, block and score}] 如果notes 是空的notes:[]

notas.UpdateMany({"$and":[{"_id":"sad445"},{"notes":{"$elemMatch":{"curse":5,"block":3}}}]},{$set":{updated_at":{$date":{$numberLong":1620322881360"}}，"notes.$.score":{"vvkzo":15,"i2z4i":2,"i2z4i|pm":5},notes.$.total":100}},{多个":假})

解决方案

Demo - https://mongoplayground.net/p/VaE28ujeOPx

使用$(更新)

<块引用>

位置 $ 运算符标识数组中要更新的元素，而无需明确指定该元素在数组中的位置.

<块引用>

位置 $ 运算符充当与查询文档匹配的第一个元素的占位符，并且

<块引用>

数组字段必须作为查询文档的一部分出现.

db.collection.update({注释":{"$elemMatch": { "block": 2, "curse": 5 }}},{$set: { "notes.$.score.b4": 40 }})

<小时>

阅读upsert:真实

<块引用>

可选.当为真时，update() 要么:

如果没有文档与查询匹配，则创建一个新文档.更多详细信息请参见 upsert 行为.更新匹配的单个文档查询.如果 upsert 和 multi 都为 true 并且没有文档匹配查询，更新操作只插入一个文档.

为避免多次更新插入，请确保查询字段是唯一的索引.有关示例，请参阅带有唯一索引的 Upsert.

默认为false，不匹配时不插入新文档找到了.

<小时>

更新

演示 - https://mongoplayground.net/p/iQQDyjG2a_B

使用 $function

db.collection.update({_id":sad445"；},[{$set:{注意:{$函数:{正文:功能(注释){var 记录 = { 诅咒:5，块:2，得分:{ b4:40 } };if(!notes || !notes.length) { 返回 [记录];}//创建新记录并在没有笔记的情况下返回变量更新 = 假；for (var i=0; i 

I need to update or create if not exist, specific obj,set score.b1 =50 and total=100 where object match curse=5 block=2

{ "_id":"sad445"
  "year":2020,
  "grade":4,
  "seccion":"A",
    "id": 100,
  "name": "pedro",
  "notes":[{"curse":5, 
          "block":1, 
          "score":{ "a1": 5,"a2": 10, "a3": 15},
          "total" : 50
          },{
          "curse":5, 
          "block":2, 
          "score":{ "b1": 10,"b2": 20, "b3": 30},
          "total" : 20
          }
   ]
}

I can update all obj but I need to update or create specific elem from the score and not all. and/or create objs "notes":[{curse, block and score}] if notes is empty notes:[]

notas.UpdateMany(
{"$and":[{"_id":"sad445"},{"notes":{"$elemMatch":{"curse":5,"block":3}}}]},

{"$set":{"updated_at":{"$date":{"$numberLong":"1620322881360"}},

"notes.$.score":{"vvkzo":15,"i2z4i":2,"i2z4i|pm":5},
"notes.$.total":100}},

{"multiple":false})

解决方案

Demo - https://mongoplayground.net/p/VaE28ujeOPx

Use $ (update)

The positional $ operator identifies an element in an array to update without explicitly specifying the position of the element in the array.

the positional $ operator acts as a placeholder for the first element that matches the query document, and

the array field must appear as part of the query document.

db.collection.update({
  "notes": {
    "$elemMatch": { "block": 2, "curse": 5 }
  }
},
{
  $set: { "notes.$.score.b4": 40 }
})

---

Read upsert: true

Optional. When true, update() either:

Creates a new document if no documents match the query. For more details see upsert behavior. Updates a single document that matches the query. If both upsert and multi are true and no documents match the query, the update operation inserts only a single document.

To avoid multiple upserts, ensure that the query field(s) are uniquely indexed. See Upsert with Unique Index for an example.

Defaults to false, which does not insert a new document when no match is found.

---

Update

Demo - https://mongoplayground.net/p/iQQDyjG2a_B

Use $function

db.collection.update(
    { "_id": "sad445" },
    [
      {
        $set: {
          notes: {
            $function: {
              body: function(notes) {
                        var record = { curse:5, block:2, score:{ b4:40 } };
                        if(!notes || !notes.length) { return [record]; } // create new record and return in case of no notes
                        var updated = false;
                        for (var i=0; i < notes.length; i++) {
                            if (notes[i].block == 2 && notes[i].curse == 5) { // check condition for update
                                updated = true;
                                notes[i].score.b4=40; break; // update here
                            }
                        }
                        if (!updated) notes.push(record); // if no update push the record in notes array
                        return notes;
                    },
              args: [
                "$notes"
              ],
              lang: "js"
            }
          }
        }
      }
    ]
)

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