CODEWITHSUNDEEP
c#mongodb
user1275011
user1275011

Reputation: 1772

MongoDB Updating multiple records based on the Nth value in an array using the C# driver

Suppose I have the following documents inside a collection:

[{ id:1, items: [1, 4, 1], flag:false},
{ id:2, items: [3, 1, 3], flag:false },
{ id:3, items: [2, 4, 6], flag:false },
{ id:4, items: [8, 7, 2], flag:false }]

I am required to Set flag to true if items[1] == 4. So, the state of the collection after the update would be:

{ id:1, items: [1, 4, 1], flag:true},
{ id:2, items: [3, 1, 3], flag:false },
{ id:3, items: [2, 4, 6], flag:true},
{ id:4, items: [8, 7, 2], flag:false }

How do I do this using the C# driver?

Thanks!

Upvotes: 3

Views: 2117

Answers (2)

Grant
Grant

Reputation: 2305

If you are using the second version of MongoDB.Driver (2.0.0-beta2) you can do this:

var client = new MongoClient(connectionString);
var database = client.GetDatabase("test");
var collection = database.GetCollection<Entity>("entities");

await collection.UpdateManyAsync(
    filter => filter.Items[1] == 4,
    update => update.Set(ent => ent.Flag, true));

Assuming you have Entity class:

public class Entity
{
    public int Id { get; set; }
    public List<int> Items { get; set; }
    public bool Flag { get; set; }
}

Upvotes: 5

Disposer
Disposer

Reputation: 6371

Use this query to do the update via mongo shell

db.test.update({'items.1' : 4}, { $set :  { flag : true}}, {multi : true})

The C# code would be:

var url = new MongoUrl("mongodb://localhost:27017");
var client = new MongoClient(url);
var server = client.GetServer();
var database = server.GetDatabase("test");
var collection = database.GetCollection("test");

var query = Query.EQ("items.1", 4);
var update = Update.Set("flag", true);

collection.Update(query, update, UpdateFlags.Multi);

Upvotes: 3

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