public class Person
{ [BsonId] [BsonRepresentation(BsonType.String)] public string Id { get; set; } public string FirstName { get; set; } public string Surname { get; set; }
}
public class Peger
{ public int Count { get; set; } public int Page { get; set; } public int Size { get; set; } public IEnumerable<Person> Items { get; set; }
}
class Program
{ static async Task Main(string[] args) { var client = new MongoClient(); var database = client.GetDatabase("pager_test"); var collection = database.GetCollection<Person>(nameof(Person)); int page = 1; int pageSize = 5; var results = await GetPagerResultAsync(page, pageSize, collection); } private static async Task<Peger> GetPagerResultAsync(int page, int pageSize, IMongoCollection<Person> collection) { // count facet, aggregation stage of count var countFacet = AggregateFacet.Create("countFacet", PipelineDefinition<Person, AggregateCountResult>.Create(new[] { PipelineStageDefinitionBuilder.Count<Person>() })); // data facet, we’ll use this to sort the data and do the skip and limiting of the results for the paging. var dataFacet = AggregateFacet.Create("dataFacet", PipelineDefinition<Person, Person>.Create(new[] { PipelineStageDefinitionBuilder.Sort(Builders<Person>.Sort.Ascending(x => x.Surname)), PipelineStageDefinitionBuilder.Skip<Person>((page - 1) * pageSize), PipelineStageDefinitionBuilder.Limit<Person>(pageSize), })); var filter = Builders<Person>.Filter.Empty; var aggregation = await collection.Aggregate() .Match(filter) .Facet(countFacet, dataFacet) .ToListAsync(); var count = aggregation.First() .Facets.First(x => x.Name == "countFacet") .Output<AggregateCountResult>() ?.FirstOrDefault() ?.Count ?? 0; var data = aggregation.First() .Facets.First(x => x.Name == "dataFacet") .Output<Person>(); return new Pager { Count = (int)count / pageSize, Size = pageSize, Page = page, Items = data }; }
}