I am using C# and I am having trouble loading large files into a binary field use byte arrays.
Basically, if I load a file that is too large, I get memory problems.
Is there a way to load a file into a binary field without using large amounts of ram, i.e. avoid loading the file into memory first?
If it helps, I am using Advantage Database Server and this is using a winforms app not a web app.
Regards
The AdsExtendedReader.SetBytes can be used to load the blob in chunks. It encapsulates the the call to the AdsSetBinary() that Jeremy mentioned.
You can use the Advantage Client Engine (ACE) directly and call the AdsSetBinary API to set the blob in chunks. Sorry I don't have time right now to write an example for you. You will need to add this prototype to your c# file:
[DllImport("ace32.dll", CharSet=CharSet.Ansi, CallingConvention=CallingConvention.Winapi )]
public static extern uint AdsSetBinary( IntPtr hTable, String pucFldName, ushort usBinaryType, uint ulTotalLength, uint ulOffset, byte[] pucBuf, uint ulLen );
And here is a link to the C API reference:
To get the handle to pass the API, see the AdsExtendedReader.AdsHandle documentation.
Update: I just saw Alex's answer and it is better than mine, I didn't know that we already wrapped the AdsSetBinary call with a .NET method. You might want to mark his answer as the correct answer to this question. :)
Unless you choose to simply add a reference in the database to where the file is located it must go through memory first, so id advise looking into a solution that loads the file x bytes at a time.
I've done this before using "UPDATE .WRITE" I read chunks of the file from a stream and append the data to the database field. Search for .WRITE on this page: http://msdn.microsoft.com/en-us/library/ms177523.aspx.
Unfortunately that is for SQL Server. I think Advantage Database Server will vary a bit here, but maybe this will send you in the right direction.
