c# - 无法执行事务操作，因为有待处理的请求在工作

Question

背景

我有一些代码可以打开一个 sql 连接，开始一个事务并对数据库执行一些操作。此代码从数据库创建一个对象(出队)，获取一些值并将其保存回来。整个操作需要在事务中进行。所有代码在没有事务的情况下都能完美运行。

using (var connection = new SqlConnection(connectionString))
{
    connection.Open();
    var transaction = connection.BeginTransaction();
    try
    {                       
        var myObject = foo.Dequeue(connection, transaction);

        var url = myObj.GetFilePathUri(connection, transaction);

        //some other code that sets object values

        myObj.SaveMessage(connection, transaction);
        transaction.Commit(); //error here
    }
    catch(Exception ex)
    {                    
        transaction.Rollback();
        //logging                
    }
    finally
    {
        //cleanup code
    }
}

dequeue方法代码

public foo Dequeue(SqlConnection connection, SqlTransaction transaction)
{
    using (var command = new SqlCommand(DEQUEUE_SPROC, connection) {CommandType = CommandType.StoredProcedure, Transaction = transaction})
    {
        var reader = command.ExecuteReader();
        if (reader.HasRows)
        {
            reader.Read();
            ID = (Guid) reader["ID"];
            Name = reader["Name"].ToString();
            return this;
        }
        return null;
    }
}

获取路径代码

public string GetFilePathUri(SqlConnection connection, SqlTransaction transaction)
{
    using (var command = new SqlCommand(FILEPATH_SPROC, connection) {CommandType = CommandType.StoredProcedure, Transaction = transaction})
    {
        var reader = command.ExecuteReader();
        if (reader.HasRows)
        {
            reader.Read();
            return reader["Path"].ToString();
        }
        return "";
    }
}

保存代码

public void SaveMessage(SqlConnection connection, SqlTransaction transaction)
{
    using (var command = new SqlCommand(SAVE_SPROC, connection) {CommandType = CommandType.StoredProcedure, Transaction = transaction})
    {
        command.Parameters.Add("@ID", SqlDbType.UniqueIdentifier).Value = ID;
        command.Parameters.Add("@Name", SqlDbType.VarChar).Value = Name;
        //other object params here
        command.ExecuteNonQuery();
    }
}

问题

调用 transaction.Commit() 时，出现以下错误:

The transaction operation cannot be performed because there are pending requests working on this transaction.

我做错了什么？

编辑:快速编辑说我已经在 SO 上阅读了关于这个问题的其他问题，但找不到任何与 ADO.net 相关的内容

Answer 1

我以前遇到过这个问题，问题是需要关闭阅读器。试试这个:

public foo Dequeue(SqlConnection connection, SqlTransaction transaction)
{
    using (var command = new SqlCommand(DEQUEUE_SPROC, connection) {CommandType = CommandType.StoredProcedure, Transaction = transaction})
    {
        var reader = command.ExecuteReader();
        if (reader.HasRows)
        {
            reader.Read();
            ID = (Guid) reader["ID"];
            Name = reader["Name"].ToString();
            reader.Close();//Closing the reader
            return this;
        }
        return null;
    }
}


public string GetFilePathUri(SqlConnection connection, SqlTransaction    transaction)
{
    string filePathUri = "";
    using (var command = new SqlCommand(FILEPATH_SPROC, connection) {CommandType = CommandType.StoredProcedure, Transaction = transaction})
    {
        var reader = command.ExecuteReader();
        if (reader.HasRows)
        {
            reader.Read();
            filePathUri = reader["Path"].ToString();
        }
        reader.Close();//Closing the reader
    }
    return filePathUri;
}