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Perform multiple updates with bulk operations and update elements in an array in MongoDB
For this, use initializeOrderedBulkOp(). It initializes and returns a new Bulk() operations builder for a collection. The builder constructs an ordered list of write operations that MongoDB executes in bulk.
Let us create a collection with documents −
>db.demo550.insertOne({"Name":"Chris","details":[{"Marks":49,Result:"fail"},{"Marks":58,Result:"fail"}]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e8e35bd9e5f92834d7f05e4")
}Display all documents from a collection with the help of find() method −
> db.demo550.find();
This will produce the following output −
{ "_id" : ObjectId("5e8e35bd9e5f92834d7f05e4"), "Name" : "Chris", "details" : [ { "Marks" : 49, "Result" : "fail" }, { "Marks" : 58, "Result" : "fail" } ] }Following is the query to update elements in an array in MongoDB and perform bulk operations −
> var all= db.demo550.initializeOrderedBulkOp(),
... itr = 0;
> db.demo550.find({ "Name": "Chris", "details.Result": "fail" }).forEach(function(doc) {
... doc.details.filter(function(d){ return d.Result = "fail" }).forEach(function(d) {
... all.find({ "_id": doc._id, "details.Result": "fail" }).updateOne({
... "$set": { "details.$.Result": "PASS" }
... });
... itr++;
... if ( itr % 10== 0 ) {
... all.execute();
... all = db.demo550.initializeOrderedBulkOp();
... }
... });
... if ( itr % 10 != 0 )
... all.execute();
... });Display all documents from a collection with the help of find() method −
> db.demo550.find();
This will produce the following output −
{ "_id" : ObjectId("5e8e35bd9e5f92834d7f05e4"), "Name" : "Chris", "details" : [ { "Marks" : 49, "Result" : "PASS" }, { "Marks" : 58, "Result" : "PASS" } ] }
Updated on: 14-May-2020
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