Oracle.DataAccess.Client.OracleCommand ExecuteReaderAsync [英] Oracle.DataAccess.Client.OracleCommand ExecuteReaderAsync

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IT屋！