Question

我在Windows 7（版本6.1 Build 7601：Service Pack 1）和visual studio 2010上安装了SQL server express 2008 SP1。

我正在尝试创建一个存储过程CLR，用于使用以下代码将文件插入到文件流中。

using System;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;
using System.IO;
using System.Security.Principal;

public partial class StoredProcedures
{
     [Microsoft.SqlServer.Server.SqlProcedure]
     public static void sp_fileController(String friendlyName, String filePath)
{
    SqlParameter fDataParam = new System.Data.SqlClient.SqlParameter("@fData", SqlDbType.VarBinary, -1);
    SqlParameter fNameParam = new System.Data.SqlClient.SqlParameter("@fName", SqlDbType.NVarChar, 300);

    WindowsIdentity newId = SqlContext.WindowsIdentity;
    WindowsImpersonationContext impersonatedUser = newId.Impersonate();

    try
    {
        string cs = @"Server=[myservername];Integrated Security=true";
        using (SqlConnection con = new SqlConnection(cs))
        {
            con.Open();
            SqlTransaction objSqlTran = con.BeginTransaction();

            //string sql = "INSERT INTO fileStreamTest VALUES ((Cast('' As varbinary(Max))), @fName, default); Select fData.PathName() As Path From fileStreamTest Where fId = SCOPE_IDENTITY()";//OUTPUT inserted.fid 
            SqlCommand insertFileCommand = con.CreateCommand();

            insertFileCommand.Transaction = objSqlTran;

            insertFileCommand.CommandText = "INSERT INTO fileStreamTest.dbo.fileStreamTest (RowGuid, fData) VALUES (@FileID, CAST ('' as varbinary(max)))";

            Guid newFileID = Guid.NewGuid();

            insertFileCommand.Parameters.Add("@FileID", SqlDbType.UniqueIdentifier).Value = newFileID;

            insertFileCommand.ExecuteNonQuery();

            SqlCommand getPathAndTokenCommand = con.CreateCommand();

            getPathAndTokenCommand.Transaction = objSqlTran;

            getPathAndTokenCommand.CommandText =
                "SELECT fData.PathName(), GET_FILESTREAM_TRANSACTION_CONTEXT() " +
                "FROM   fileStreamTest.dbo.fileStreamTest " +
                "WHERE  rowGuid = @FileID";

            getPathAndTokenCommand.Parameters.Add("@FileID", SqlDbType.UniqueIdentifier).Value = newFileID;

            SqlDataReader tokenReader = getPathAndTokenCommand.ExecuteReader(CommandBehavior.SingleRow);

            tokenReader.Read();

            SqlString filePathName = tokenReader.GetSqlString(0);

            SqlBinary fileToken = tokenReader.GetSqlBinary(1);

            tokenReader.Close();

            SqlFileStream sqlFile = new SqlFileStream(filePathName.Value, fileToken.Value, System.IO.FileAccess.ReadWrite);
            sqlFile.Close();

            objSqlTran.Rollback();
            //objSqlTran.Commit();
            con.Close();

        }
    }
    finally
    {
        impersonatedUser.Undo();
    }
}
};

然而，当它到达界限时：

SqlFileStream sqlFile = new SqlFileStream(filePathName.Value, fileToken.Value, System.IO.FileAccess.ReadWrite);

我明白了：

在执行用户定义的例程或聚合“sp_fileController”期间发生.NET Framework错误：

System.ComponentModel.Win32Exception: The request is not supported
System.ComponentModel.Win32Exception: 
   at System.Data.SqlTypes.SqlFileStream.OpenSqlFileStream(String path, Byte[] transactionContext, FileAccess access, FileOptions options, Int64 allocationSize)
   at System.Data.SqlTypes.SqlFileStream..ctor(String path, Byte[] transactionContext, FileAccess access, FileOptions options, Int64 allocationSize)
   at System.Data.SqlTypes.SqlFileStream..ctor(String path, Byte[] transactionContext, FileAccess access)
   at StoredProcedures.sp_fileController(String friendlyName, String filePath)

有谁能告诉我如何解决这个问题？只是我不能用sql 2008 express edition以这种方式执行代码吗？

Answer 1

听起来很奇怪，Microsoft 故意阻止在SQL CLR程序集中使用SqlFileStream类用法（即使您授予EXTERNAL_ACCESS或将程序集声明为{{ 1}}）你可以阅读Microsoft Connect issue 768308。

但是你可以通过SqlBytes类型访问FILESTREAM（在blog post找到一个非常好的提示）..至少对于只读用途，我从未尝试过编写。

我复制过去的代码以防博客消失（在略有改进的版本中并妥善处理对象）：

UNSAFE

我可以确认这肯定适用于只读访问。我从未尝试过写访问（我正在从外部C＃Windows服务或Web应用程序编写FILESTREAM数据）。

sqlFileStream System.ComponentModel.Win32Exception：不支持该请求

1 个答案: