/C#/Paging thru result from mongodb in C#

Paging thru result from mongodb in C#

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
        };
    }
}

Source: stackoverflow.com

Similar codes

0 vote256 views1 answer
C# see if string is int
C#
0 vote247 views1 answer
Reverse a linked list C#
C#
1 vote252 views1 answer
How to add a gameobject
C#
0 vote258 views1 answer
C# programiticall change selected index of databound datagridviewcombo box
C#
0 vote233 views1 answer
Windows form button border color
C#
7 votes229 views2 answers
Set focus ui unity
C#
3 votes269 views1 answer
Unity mouse scroll wheel axis
C#Unity
0 vote241 views1 answer
Barcode print c#
C#
0 vote234 views1 answer
Asp net identity add a unique fields to user
C#
4 votes231 views3 answers
Mysql list table columns
C#