Thanks, I will do so.



_____

From: firebird-support@yahoogroups.com
[mailto:firebird-support@yahoogroups.com] On Behalf Of Helen Borrie
Sent: Wednesday, December 07, 2005 5:19 PM
To: firebird-support@yahoogroups.com
Subject: Re: [firebird-support] C# .Net provider and binary field problem




In approving this for the support list I inadvertently failed to notice
that it's actually a net provider problem. My apologies.

Please re-post to the firebird-net-provider list.

^heLen

At 07:40 PM 7/12/2005 +0000, you wrote:

>I want to have a binary field (SHA1 Hash value). I could use a BLOB
>for it. However, I also want to use this field as a primary key.
>BLOBS can not be used as either indexes or primary keys.
>
> >From what I've read, it appears that I could represent a binary field
>as a CHAR with character set assigned "OCTETS". It appears that the
>1.7 Firebird .Net data provider allows GUIDS to be represented that
>way (CHAR(16) CHARACTER SET OCTETS).
>
> >From what testing I've done, I CAN NOT move binary data into a CHAR
>(20) CHARACTER SET OCTETS. It appears that the .Net data provider
>does not handle this correctly.
>
>If I try to set the command parameter to FbDbType.Char, the .Net data
>provide calls the ToString method on the object passed in as the
>value. For a byte[] object, that always returned the system type
>string "System.byte[]". If I set the data type to FbDbType.Binary I
>get an internal SQL error of -303 (an undocumented error).
>
>
> SHA1 sha = new SHA1CryptoServiceProvider();
>
> string cmdtext = "INSERT INTO CONTENT (SHA1_HASH,
>PART_SIZE, CONTENTX) VALUES (@sha, @size, @content)";
>
> FbConnection fbconn = new FbConnection(connectionString);
> FbCommand fbcommand = new FbCommand(cmdtext, fbconn);
> FbTransaction fbtrans = null;
> FbParameter fbparam;
>
>
> /* create some random content */
> byte[] data = new byte[33];
> Random rn = new Random();
>
> for (int i = 0; i < data.Length; i++)
> data[i] = (byte) rn.Next(0, 255);
>
>
> fbparam = new FbParameter("@sha", FbDbType. Binary); <-
>PROBLEM LINE
> fbparam.Value = sha.ComputeHash(data);
> fbcommand.Parameters.Add(fbparam);
>
> fbparam = new FbParameter("@size", FbDbType.BigInt);
> fbparam.Value = data.Length;
> fbcommand.Parameters.Add(fbparam);
>
> fbparam = new FbParameter("@content", FbDbType.Binary);
> fbparam.Value = data;
> fbcommand.Parameters.Add(fbparam);
>
> try
> {
> fbconn.Open();
> fbtrans = fbconn.BeginTransaction();
> fbcommand.Transaction = fbtrans;
> fbcommand.ExecuteNonQuery();
> fbtrans.Commit();
> }
>
> catch (Exception ex)
> {
> if (fbtrans != null)
> fbtrans.Rollback();
>
> MessageBox.Show(ex.Message);
> }
>
> finally
> {
> fbconn.Close();
> }
>
>
>Am I missing something? If I can not directly store a binary field,
>I'll BASE64 the SHA1 value to get a character string and store the
>SHA1 as character data. I would however prefer to keep the more
>compact binary representation.
>
>
>
>
>
>
>
>
>
>
>
>
>
>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>
>Visit http://firebird.sourceforge.net and click the Resources item
>on the main (top) menu. Try Knowledgebase and FAQ links !
>
>Also search the knowledgebases at http://www.ibphoenix.com
>
>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>
>Yahoo! Groups Links
>
>
>
>

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Visit http://firebird.sourceforge.net and click the Resources item
on the main (top) menu. Try Knowledgebase and FAQ links !

Also search the knowledgebases at http://www.ibphoenix.com

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++





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