Question

I ask this question as a followup of this question.

A solution that uses bcp and xp_cmdshell, that is not my desired solution, has been posted here.

I am new to c# (since I am a Delphi developer) anyway I was able to create a simple CLR stored procedure by following a tutorial.

My task is to move a file from the client file system to the server file system (the server can be accessed using remote IP, so I cannot use a shared folder as destination, this is why I need a CLR stored procedure).

So I plan to:

1. store from Delphi the file in a varbinary(max) column of a temporary table
2. call the CLR stored procedure to create a file at the desired path using the data contained in the varbinary(max) field

Imagine I need to move C:\MyFile.pdf to Z:\MyFile.pdf, where C: is a harddrive on local system and Z: is an harddrive on the server. C is in New York, Z is in London and there is no VPN between them, just https connection.

I provide the code below (not working) that someone can modify to make it work? Here I suppose to have a table called MyTable with two fields: ID (int) and DATA (varbinary(max)). Please note it doesn’t make a difference if the table is a real temporary table or just a table where I temporarly store the data. I would appreciate if some exception handling code is there (so that I can manage an “impossible to save file” exception).

I would like to be able to write a new file or overwrite the file if already existing.

[Microsoft.SqlServer.Server.SqlProcedure]
public static void VarbinaryToFile(int TableId)
{
   using (SqlConnection connection = new SqlConnection("context connection=true"))
   {
      connection.Open();
      SqlCommand command = new SqlCommand("select data from mytable where ID = @TableId", connection);
      command.Parameters.AddWithValue("@TableId", TableId);
      // This was the sample code I found to run a query
      //SqlContext.Pipe.ExecuteAndSend(command);
      // instead I need something like this (THIS IS META_SYNTAX!!!):
      SqlContext.Pipe.ResultAsStream.SaveToFile('z:\MyFile.pdf');
   }
}

(one subquestion is: is this approach correct or there is a way to directly pass the data to the CLR stored procedure so I don’t need to use a temp table?)

If the subquestion’s answer is No, could you describe the approach of avoiding a temp table? So is there a better way then the one I describe above (=temp table + Stored procedure)? A way to directly pass the dataastream from the client application to the CLR stored procedure? (my files can be any size but also very big)

Answer 1

After some research I conclude that it makes no sense, it is better to drop the support of 2005 and use 2008 fielstream feature. I can have a conditional logic to choose between 2005 and 2008 and use filestream only for 2005.