如果集合中的任何属性具有“x”字，如何过滤集合中的文档？ （MongoDB 驱动程序，C#）

Question

Let's say I have documents in a collection called "alerts" with the following structure:

{
    "_id": {
        "$oid": "5f299ed8905bcf0001cd9a56"
    },
    "CreatedDate": {
        "$date": "2020-08-04T17:46:00.862Z"
    },
    "Name": "Alert name",
    "Description": "Alert description",
    "AlertTypeId": {
        "$oid": "5f299ea7905bcf0001cd9a54"
    }
    "AlertTrigger": {
        "Variation": "moreThan",
        "Amount": 5
    },
    "Emails": ["hello@hotmail.com", "test@gmail.com"]
}

In my .Net app I have the class representation as:

[BsonCollection("alerts")]
public class Alert
{
    public ObjectId Id { get; set; }

    public DateTime CreatedDate { get; set; }

    public string Name { get; set; }

    public string Description { get; set; }

    [BsonRepresentation(BsonType.ObjectId)]
    public string AlertTypeId { get; set; }

    public AlertTrigger AlertTrigger { get; set; }

    public ICollection<string> Emails { get; set; }
}

public class AlertTrigger
{
    public string Variation { get; set; }

    public double Amount { get; set; }
}

What I would like to do is to filter documents that contain certain "keyword" in any of their properties. For example, if I filter by the word "moreThan" or the word "hello", the element above would be found, because they are contained in its properties.

How can I achieve this using MongoDB Driver, LinQ, C# ?

Answer 1

The C# Linq abstraction does not contain a way to do this. However, in MongoDB, you'll be able to create a text index on all the fields in your collection.

db.collection.createIndex( { "$**": "text" } )

Then you'll be able to do a text search on your collection in C# by writing the following.

var client = new MongoClient();
var db = client.GetDatabase("text");
var collection = db.GetCollection<Alert>("alerts");

var filter = Builders<Alert>.Filter.Text("moreThan");

var result = await collection.Find(filter).ToListAsync();