How to use $push update modifier in MongoDB and C#, when updating an array in a document

问题

I've run the following code in mongo shell:

db.unicorns.insert({name:  'Dunx',  loves:  ['grape',  'watermelon']});

and now I've something like this in my MongoDB collection:

{name: 'Dunx', loves: ['grape', 'watermelon']}

As you can see loves is an array.

Question

How can I write C# code, with the official C# driver, that does the following:

db.unicorns.update({name: 'Aurora'}, {$push: {loves: 'sugar'}})

The above code runs just fine in mongo shell.

回答1:

it should be something like this:

unicorns.Update(Query.EQ("name", "Aurora"), Update.Push("loves", "sugar"));

回答2:

I would like to also illustrate how to do it using a different syntax

var filter = Builders<Unicorn>
             .Filter.Eq(e => e.Name, "Aurora");

var update = Builders<Unicorn>.Update
        .Push<String>(e => e.Likes, like);

await fantasyContext.Unicorns.FindOneAndUpdateAsync(filter, update);

回答3:

To do this with the updated syntax and regular BsonDocuments instead of defined objects, use the following:

var filter = Builders<BsonDocument>.Filter.Eq("name": "Aurora");
var update = Builders<BsonDocument>.Update.Push("loves", "sugar"):

// you can also use the async update method from Alex's answer here
var result = fantasyContext.Unicorns.UpdateOne(filter, update);

来源：https://stackoverflow.com/questions/6649174/how-to-use-push-update-modifier-in-mongodb-and-c-when-updating-an-array-in-a