How to build filter on multiple values of same attribute in C# with MongoDb driver

Question

I am trying to create a filter on a certain attribute in my MongoDB table. I have an array of values, and I want to retrieve only results from the MongoDB that contain that value for the attribute I'm searching on.

For example:

I want to search for all of the following Ids: "12345", "23456", "34567" I have an array of these values:

var ids = ["12345", "23456", "34567"]

The filter I have currently built looks like this:

var builder = Builders<Common.Models.ServiceRequest>.Filter;
FilterDefinition<Common.Models.ServiceRequest> filter = builder.Empty;
filter = builder.Ne(x => x.Id, null);
foreach (string id in ids)
{
    filter = filter | builder.Eq(x => x.Id, id);
}

this for some reason does not seem to work, even though I am using the or(|) in MongoDriver.

Any guidance on this would be appreciated! Thanks

Answer 1

You should use the In operator to compare with a collection or array of values.

var ids = ["12345", "23456", "34567"];

var builder = Builders<Common.Models.ServiceRequest>.Filter;
FilterDefinition<Common.Models.ServiceRequest> filter = builder.Empty;
filter = builder.Ne(x => x.Id, null);
builder.In(x => x.Id, ids);

The In filter takes an IEnumerable so you can use it directly with lists, arrays or any other enumerable.