Method SingleOrDefaultAsync
SingleOrDefaultAsync<TSource>(IMongoQueryable<TSource>, CancellationToken)
Returns the only element of a sequence, or a default value if the sequence is empty; this method throws an exception if there is more than one element in the sequence.
public static Task<TSource> SingleOrDefaultAsync<TSource>(this IMongoQueryable<TSource> source, CancellationToken cancellationToken = default)Parameters
sourceIMongoQueryable<TSource>An IMongoQueryable<T> to return the single element of.
cancellationTokenCancellationTokenThe cancellation token.
Returns
- Task<TSource>
The single element of the input sequence, or default(
TSource) if the sequence contains no elements.
Type Parameters
TSourceThe type of the elements of
source.
SingleOrDefaultAsync<TSource>(IMongoQueryable<TSource>, Expression<Func<TSource, bool>>, CancellationToken)
Returns the only element of a sequence that satisfies a specified condition or a default value if no such element exists; this method throws an exception if more than one element satisfies the condition.
public static Task<TSource> SingleOrDefaultAsync<TSource>(this IMongoQueryable<TSource> source, Expression<Func<TSource, bool>> predicate, CancellationToken cancellationToken = default)Parameters
sourceIMongoQueryable<TSource>An IMongoQueryable<T> to return a single element from.
predicateExpression<Func<TSource, bool>>A function to test an element for a condition.
cancellationTokenCancellationTokenThe cancellation token.
Returns
- Task<TSource>
The single element of the input sequence that satisfies the condition in
predicate, or default(TSource) if no such element is found.
Type Parameters
TSourceThe type of the elements of
source.