/// <summary>Returns the first element of a sequence query</summary>
public static Task <int> CountAsync <T>(this IFdbAsyncSequenceQueryable <T> query, CancellationToken ct = default(CancellationToken))
{
if (query == null)
{
throw new ArgumentNullException(nameof(query));
}
var expr = FdbQueryExpressions.Single <T, int>(
(FdbQuerySequenceExpression <T>)query.Expression,
"CountAsync",
(source, _ct) => source.CountAsync(_ct)
);
return(query.Provider.CreateQuery <int>(expr).ExecuteSingle(ct));
}
/// <summary>Returns the first element of a sequence query</summary>
public static Task <T> FirstOrDefaultAsync <T>(this IFdbAsyncSequenceQueryable <T> query, CancellationToken ct = default(CancellationToken))
{
if (query == null)
{
throw new ArgumentNullException(nameof(query));
}
if (ct.IsCancellationRequested)
{
return(Task.FromCanceled <T>(ct));
}
var expr = FdbQueryExpressions.Single <T, T>(
(FdbQuerySequenceExpression <T>)query.Expression,
"FirstOrDefaultAsync",
(source, _ct) => source.FirstOrDefaultAsync(_ct)
);
return(query.Provider.CreateQuery <T>(expr).ExecuteSingle(ct));
}