/// <summary>
/// Appends a $graphLookup stage to the pipeline.
/// </summary>
/// <typeparam name="TResult">The type of the result.</typeparam>
/// <typeparam name="TFrom">The type of the from documents.</typeparam>
/// <param name="aggregate">The aggregate.</param>
/// <param name="from">The from collection.</param>
/// <param name="connectFromField">The connect from field.</param>
/// <param name="connectToField">The connect to field.</param>
/// <param name="startWith">The start with value.</param>
/// <param name="as">The as field.</param>
/// <param name="depthField">The depth field.</param>
/// <returns>The fluent aggregate interface.</returns>
public static IAggregateFluent <BsonDocument> GraphLookup <TResult, TFrom>(
this IAggregateFluent <TResult> aggregate,
IMongoCollection <TFrom> from,
FieldDefinition <TFrom, BsonValue> connectFromField,
FieldDefinition <TFrom, BsonValue> connectToField,
AggregateExpressionDefinition <TResult, BsonValue> startWith,
FieldDefinition <BsonDocument, IEnumerable <BsonDocument> > @as,
FieldDefinition <BsonDocument, int> depthField = null)
{
Ensure.IsNotNull(aggregate, nameof(aggregate));
return(aggregate.AppendStage(PipelineStageDefinitionBuilder.GraphLookup(from, connectFromField, connectToField, startWith, @as, depthField)));
}
/// <summary>
/// Appends a $graphLookup stage to the pipeline.
/// </summary>
/// <typeparam name="TResult">The type of the result.</typeparam>
/// <typeparam name="TNewResult">The type of the new result (must be same as TResult with an additional as field).</typeparam>
/// <typeparam name="TFrom">The type of the from documents.</typeparam>
/// <typeparam name="TConnectFrom">The type of the connect from field (must be either TConnectTo or a type that implements IEnumerable{TConnectTo}).</typeparam>
/// <typeparam name="TConnectTo">The type of the connect to field.</typeparam>
/// <typeparam name="TStartWith">The type of the start with expression (must be either TConnectTo or a type that implements IEnumerable{TConnectTo}).</typeparam>
/// <typeparam name="TAs">The type of the as field.</typeparam>
/// <param name="aggregate">The aggregate.</param>
/// <param name="from">The from collection.</param>
/// <param name="connectFromField">The connect from field.</param>
/// <param name="connectToField">The connect to field.</param>
/// <param name="startWith">The start with value.</param>
/// <param name="as">The as field.</param>
/// <param name="options">The options.</param>
/// <returns>The fluent aggregate interface.</returns>
public static IAggregateFluent <TNewResult> GraphLookup <TResult, TFrom, TConnectFrom, TConnectTo, TStartWith, TAs, TNewResult>(
this IAggregateFluent <TResult> aggregate,
IMongoCollection <TFrom> from,
Expression <Func <TFrom, TConnectFrom> > connectFromField,
Expression <Func <TFrom, TConnectTo> > connectToField,
Expression <Func <TResult, TStartWith> > startWith,
Expression <Func <TNewResult, TAs> > @as,
AggregateGraphLookupOptions <TFrom, TFrom, TNewResult> options = null)
where TAs : IEnumerable <TFrom>
{
Ensure.IsNotNull(aggregate, nameof(aggregate));
return(aggregate.AppendStage(PipelineStageDefinitionBuilder.GraphLookup(from, connectFromField, connectToField, startWith, @as, options, aggregate.Options?.TranslationOptions)));
}
public void GraphLookup_with_one_to_one_parameters_should_return_expected_result()
{
RequireServer.Check().Supports(Feature.AggregateGraphLookupStage);
var database = GetDatabase();
var collection = database.GetCollection <OneToOne>("collectionOneToOne");
var result = PipelineStageDefinitionBuilder.GraphLookup(
from: collection,
connectFromField: x => x.From,
connectToField: x => x.To,
startWith: (OneToOne x) => x.From,
@as: (OneToOneResult x) => x.Matches);
RenderStage(result).Document.Should().Be(
@"{
$graphLookup : {
from : 'collectionOneToOne',
connectFromField : 'From',
connectToField : 'To',
startWith : '$From',
as : 'Matches'
}
}");
}
