/// <summary>
/// 通过Aggregate统计查询
/// </summary>
public List <R> Aggregate <R>(PipelineDefinition <T, R> pipeline)
{
var cursor = MongoCollection.AggregateAsync(pipeline).Result;
var result = cursor.ToList();
return(result);
}
public async Task <IEnumerable <TDocument> > Aggregate(IWorkContext context, PipelineDefinition <TDocument, TDocument> pipeline, AggregateOptions options = null)
{
Verify.IsNotNull(nameof(context), context);
using (var cursor = await MongoCollection.AggregateAsync(pipeline, options, context.CancellationToken))
{
return(await cursor.ToListAsync(context.CancellationToken));
}
}
public async Task <int> GetHighestTagNumberAsync()
{
var result = await MongoCollection
.AggregateAsync(
PipelineDefinition <Resident, BsonDocument> .Create(
new BsonDocument("$unwind", "$tags"),
new BsonDocument(
"$group", new BsonDocument
{
{ "_id", "$_id" },
{ "max", new BsonDocument("$max", "$tags") }
}),
new BsonDocument("$sort", new BsonDocument("max", -1)),
new BsonDocument("$limit", 1)));
return(result.Single()["max"].AsInt32);
}
