SQL Server 2008:FileStream插入失败w/.NET 3.5SP1

Question

我已经配置了一个带有FileStream组的数据库,并且有一个带有文件类型的表.尝试插入流式文件时,在创建表行之后,我的查询读取文件路径,缓冲区返回空文件路径.我似乎无法弄明白为什么.这是表创建脚本:

    /****** Object:  Table [dbo].[JobInstanceFile]    Script Date: 03/22/2010 18:05:36 ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

SET ANSI_PADDING ON
GO

CREATE TABLE [dbo].[JobInstanceFile](
    [JobInstanceFileId] [int] IDENTITY(1,1) NOT NULL,
    [JobInstanceId] [int] NOT NULL,
    [File] [varbinary](max) FILESTREAM  NULL,
    [FileId] [uniqueidentifier] ROWGUIDCOL  NOT NULL,
    [Created] [datetime] NOT NULL,
 CONSTRAINT [PK_JobInstanceFile] PRIMARY KEY CLUSTERED 
(
    [JobInstanceFileId] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY] FILESTREAM_ON [JobInstanceFilesGroup],
UNIQUE NONCLUSTERED 
(
    [FileId] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY] FILESTREAM_ON [JobInstanceFilesGroup]

GO

SET ANSI_PADDING OFF
GO

ALTER TABLE [dbo].[JobInstanceFile] ADD  DEFAULT (newid()) FOR [FileId]
GO

这是我的proc我调用在流文件之前创建行:

    /****** Object:  StoredProcedure [dbo].[JobInstanceFileCreate]    Script Date: 03/22/2010 18:06:23 ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

create proc [dbo].[JobInstanceFileCreate]

    @JobInstanceId int,
    @Created datetime

    as

    insert into JobInstanceFile (JobInstanceId, FileId, Created)
    values (@JobInstanceId, newid(), @Created)

    select scope_identity()
GO

最后,这是我正在使用的代码:

    public int CreateJobInstanceFile(int jobInstanceId, string filePath)
        {
            using (var connection = new SqlConnection(ConfigurationManager.ConnectionStrings["ConsumerMarketingStoreFiles"].ConnectionString))
            using (var fileStream = new FileStream(filePath, FileMode.Open))
            {
                connection.Open();

                var tran = connection.BeginTransaction(IsolationLevel.ReadCommitted);

                try 
                {
                    //create the JobInstanceFile instance
                    var command = new SqlCommand("JobInstanceFileCreate", connection) { Transaction = tran };
                    command.CommandType = CommandType.StoredProcedure;
                    command.Parameters.AddWithValue("@JobInstanceId", jobInstanceId);
                    command.Parameters.AddWithValue("@Created", DateTime.Now);

                    int jobInstanceFileId = Convert.ToInt32(command.ExecuteScalar());

                    //read out the filestream transaction context to stream the file for storage
                    command.CommandText = "select [File].PathName(), GET_FILESTREAM_TRANSACTION_CONTEXT() from JobInstanceFile where JobInstanceFileId = @JobInstanceFileId";
                    command.CommandType = CommandType.Text;
                    command.Parameters.AddWithValue("@JobInstanceFileId", jobInstanceFileId);

                    using (SqlDataReader dr = command.ExecuteReader())
                    {
                        dr.Read();

                        //get the file path we're writing out to
                        string writePath = dr.GetString(0);

                        using (var writeStream = new SqlFileStream(writePath, (byte[])dr.GetValue(1), FileAccess.ReadWrite))
                        {
                            //copy from one stream to another
                            byte[] bytes = new byte[65536];
                            int numBytes;
                            while ((numBytes = fileStream.Read(bytes, 0, 65536)) > 0)
                                writeStream.Write(bytes, 0, numBytes);
                        }
                    }

                    tran.Commit();

                    return jobInstanceFileId;
                }
                catch (Exception e)
                {
                    tran.Rollback();
                    throw e;
                }
            }
        }

有人可以让我知道我做错了什么.在代码中,以下表达式为文件路径返回null,不应该是:

//获取我们写入字符串writePath = dr.GetString(0)的文件路径;

服务器与运行代码的计算机不同,但必要的共享似乎是有序的,我也运行了以下内容:

EXEC sp_configure filestream_access_level,2

任何帮助将不胜感激.谢谢!

Answer 1

您无法在NULL值上打开SqlFileStream.更改INSERT语句以设置File = 0x,它应该开始工作.

PS.一些性能考虑:

1. 您可以通过发出带有OUTPUT子句的INSERT来避免额外的服务器往返,该子句返回新插入的blob的事务上下文和文件路径.
2. 如果您不打算从SqlFileStream中读取,请将其打开以仅写入.在这种特殊情况下,这可能不是什么大问题,因为您打开的文件是空的.但是如果你要更新一个大文件,那么为ReadWrite打开它会让Sql先复制整个文件,然后让你玩它.