问题描述
因此，因为OracleCommand类扩展了DbCommand类，所以它实现了Execute方法的异步版本.但是，我无法从Oracle找到支持该方法的对该OracleCommand类的任何引用(我正在使用11g): http://docs.oracle.com/html/E10927_01/OracleCommandClass.htm
So because the OracleCommand class extends the DbCommand class it implements the Async versions of it's Execute methods. However, I cannot find any reference to that OracleCommand class supporting these methods from Oracle (I am using 11g):http://docs.oracle.com/html/E10927_01/OracleCommandClass.htm
有人知道支持这些方法的内幕是什么吗?它们似乎是非阻塞的，并且在使用中支持取消操作(我希望坦白地说是NotImplementedException)，但是由于文档的原因，这让我感到不受支持，所以我想确保没有任何麻烦.
Do anyone know what this is doing under the hood to support these methods? They appear to be non-blocking and support cancellation in usage (I expected a NotImplementedException to be honest), but this feels unsupported to me because of the documentation so I want to make sure that there aren't any gotchas.
推荐答案
Oracle客户端不会覆盖方法的异步版本.他们使用默认的DbCommand实现，这些实现调用方法的非异步版本.
The Oracle client doesn't override the async versions of the methods. They use the default DbCommand implementnations which call the non-async versions of the methods.
例如，ExecuteNonQueryAsync的实现是:
// System.Data.Common.DbCommand
public virtual Task<int> ExecuteNonQueryAsync(CancellationToken cancellationToken)
{
if (cancellationToken.IsCancellationRequested)
{
return ADP.CreatedTaskWithCancellation<int>();
}
CancellationTokenRegistration cancellationTokenRegistration = default(CancellationTokenRegistration);
if (cancellationToken.CanBeCanceled)
{
cancellationTokenRegistration = cancellationToken.Register(new Action(this.CancelIgnoreFailure));
}
Task<int> result;
try
{
result = Task.FromResult<int>(this.ExecuteNonQuery());
}
catch (Exception ex)
{
cancellationTokenRegistration.Dispose();
result = ADP.CreatedTaskWithException<int>(ex);
}
return result;
}
如您所见，它只是简单地调用了ExecuteNonQuery(ExecuteNonQueryAsync的无参数重载调用了该版本的方法).
As you can see, it simply calls ExecuteNonQuery under the hood (the no-parameter overload of ExecuteNonQueryAsync calls this version of the method).
这篇关于Oracle.DataAccess.Client.OracleCommand ExecuteReaderAsync的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！