Mongo C# 驱动程序 - 通过嵌套动态构建过滤器

csharp
using MongoDB.Bson;
using MongoDB.Driver;
public class User
{
    public ObjectId Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
    public string City { get; set; }
}
public class Program
{
    static void MAIn(string[] args)
    {
        var client = new MongoClient("MongoDB://localhost:27017");
        var Database = client.GetDatabase("test");
        var collection = Database.Getcollection<User>("users");
        var filterBuilder = Builders<User>.Filter;
        var filter = filterBuilder.Empty; // 初始过滤器为空
        // 动态添加条件
        filter = filter & filterBuilder.Eq(u => u.City, "Beijing");
        filter = filter & filterBuilder.Gte(u => u.Age, 18);
        var users = collection.Find(filter).ToList();
        foreach (var user in users)
        {
            Console.WriteLine(user.Name);
        }
    }
}