It is necessary to update several data with one request. Here is an example request:

db.coll.update( { article: 100500 }, { $set: { a: 555 }, $pull: { arr: { t: { $lt: 20 } } } } );

Here is an example of the document itself:

 { article: 100500, a: 400, arr: [ { t: 30, b: 12, n: 90 }, { t: 10, b: 16, n: 60 } ] }

My request:

  1. Updates the value of a to 555 .
  2. Removes all elements of the arr array, where t < 20 .

The essence of the question: It is necessary to update the values ​​of b in the arr . That is, wherever n == 90 , the value of b must be changed to 777 . How can this request be supplemented to “kill 3 birds with one stone”?

The result should be such a document:

 { article: 100500, a: 555, /* Тут было: 400 */ arr: [ { t: 30, b: 777, n: 90 }, /* Тут был элемент массива */ ] }

    1 answer 1

    I assume you have the following documents in your collection.

     { "_id" : ObjectId("56b71025973d202a52a5e650"), "article" : 100500, "a" : 400, "arr" : [ { "t" : 30, "b" : 12, "n" : 90 }, { "t" : 20, "b" : 16, "n" : 60 } ] }, { "_id" : ObjectId("56b7102b973d202a52a5e651"), "article" : 100500, "a" : 400, "arr" : [ { "t" : 0, "b" : 12, "n" : 90 }, { "t" : 10, "b" : 16, "n" : 60 } ] }, { "_id" : ObjectId("56b710d4973d202a52a5e652"), "article" : 100500, "a" : 400, "arr" : [ { "t" : 30, "b" : 12, "n" : 90 }, { "t" : 27, "b" : 16, "n" : 32 } ] }

    First of all, you should know that it is not possible to update more than one element in an array using the update() method even with the multi: true updateMany() or using the updateMany() method; and all the logic behind what you are trying to do; make things more difficult.

    The best way to do this is using Bulk Operations .

    Solution for MongoDB version 3.2 or newer:

    MongoDB 3.2 does not recommend Bulk() and related methods. You need to use the .bulkWrite() method

    Here we have two options:

    1. It is necessary to use aggregation to reduce the number of documents that need to be updated. here only one stage in the chain is needed: $project where we use the $filter operator.

      let requests = [];

       db.collection.aggregate([ { "$project": { "deleteElements": { "$filter": { "input": "$arr", "as": "del", "cond": { "$lt": [ "$$del.t", 12 ] } } }, "updateElements": { "$filter": { "input": "$arr", "as": "upd", "cond": { "$and": [ { "$gte": [ "$$upd.t", 12 ] }, { "$eq": [ "$$upd.n", 90 ] } ] } } } }} ]).forEach(function(document) { document.deleteElements.forEach(function(element) { requests.push( { "updateOne": { "filter": { "_id": document._id, "arr.t": element.t }, "update": { "$pull": { "arr": element } } } } ); }); document.updateElements.forEach(function(element) { requests.push( { "updateOne": { "filter": { "_id": document._id, "arr.t": element.n }, "update": { "$set": { "arr.$.b": 777 } } } } ); }); requests.push( { "updateOne": { "filter": { "_id": document._id }, "update": { "$set": { "a": 555 } } } } ); }) db.collection.bulkWrite(requests)

    2. Using the .find() method

       db.collection.find({"article": 100500}).snapshot().forEach(function(document) { document.arr.filter(function(arr) { return arr.t < 12; }).forEach(function(element) { requests.push( { "updateOne": { "filter": { "_id": document._id, "arr.t": { "$lt": 12 }}, "update": { "$pull": { "arr": element } } } } ); }); document.arr.filter(function(arr) { return arr.n === 90; }).forEach(function(element) { requests.push( { "updateOne": { "filter": { "_id": document._id, "arr.n": 90 }, "update": { "$set": { "arr.$.b": 777 } } } } ); }); requests.push( { "updateOne": { "filter": { "_id": document._id }, "update": { "$set": { "a": 555 } } } } ); }) db.collection.bulkWrite(requests);

    Solution for MongoDB version 2.6 or newer:

     var bulk = db.collection.initializeOrderedBulkOp(); var count = 0; db.collection.find({"article": 100500}).snapshot().forEach(function(document) { document.arr.filter(function(arr) { return arr.t < 12; }).forEach(function(element) { bulk.find({ "_id": document._id, "arr.t": { "$lt": 12 } } ).updateOne({ "$pull": { "arr": element } }); count++; }); document.arr.filter(function(arr) { return arr.n === 90; }).forEach(function(element) { bulk.find({ "_id": document._id, "arr.n": 90 }).updateOne({ "$set": { "arr.$.b": 777 } }); count++; }); bulk.find( { "_id": document._id } ).updateOne( { "$set": { "a": 555 } } ); count++; if (count % 1000 === 0) { // Выпольнить после 1000 операции bulk.execute(); bulk = db.collection.initializeOrderedBulkOp(); } }) // Очистить очереди if (count > 0) { bulk.execute(); }

    To show

     { "_id" : ObjectId("56b71025973d202a52a5e650"), "article" : 100500, "a" : 555, "arr" : [ { "t" : 30, "b" : 777, "n" : 90 }, { "t" : 20, "b" : 16, "n" : 60 } ] } { "_id" : ObjectId("56b7102b973d202a52a5e651"), "article" : 100500, "a" : 555, "arr" : [ ] } { "_id" : ObjectId("56b710d4973d202a52a5e652"), "article" : 100500, "a" : 555, "arr" : [ { "t" : 30, "b" : 777, "n" : 90 }, { "t" : 27, "b" : 16, "n" : 32 } ] }