How to Handle Non-Required File Upload Fields in DALC?

Question

I'm coding an Admin form. The user may or may not update PDF file(s); if he does I'm handling it in my form coded as follows:

string fileExt = System.IO.Path.GetExtension(regFormUpload.FileName);
if (regFormUpload.HasFile)
{
    if (string.Equals(fileExt, ".pdf", StringComparison.OrdinalIgnoreCase))
    {
        Stream pdfFileStream = regFormUpload.PostedFile.InputStream;
        fileData = new byte[regFormUpload.PostedFile.ContentLength];
        pdfFileStream.Read(fileData, 0, regFormUpload.PostedFile.ContentLength);

        // Call DALC method with uploaded file(s) params
    }
    else
    {
        regFormCustVal.IsValid = false;
    }
}
else
{
    // Call DALC method indicating "null" for non-uploaded files(s)???
}

Is there a way to pass a null to the DALC/Stored Procedure? It's being stored in SQL Server as a varbinary(max) type. Previously I used to code separate methods depending on whether or not someone uploaded a file and I know there has to be an easier way but the C# syntax is escaping me.

UPDATE - 05-24-2012

I still haven't got an answer to this. In my DALC, I currently have to call several DB update methods, depending on whether files (byte[]) has been uploaded or not. Is there anyway to get around this? I have two separate file upload controls and both are non-required fields. This means I have to code up to four separate DB update methods to account for the (2^2) possibilities!

What if the extension is ".pdf2"? :) (Use string.Equals(fileExt, ".pdf", StringComparison.OrdinalIgnoreCase) — usr, May 24 '12 at 11:50
You probably already know this...for a stored proc to accept null I would declare the variable as @myvar varbinary(max) =null. In C# declare the variable as string? myvar; — developer747, May 24 '12 at 14:40
I put 50 points bounty on this and it becomes community wiki???? — IrishChieftain, May 29 '12 at 05:26

score 1 · Answer 1 · edited May 23 '17 at 12:11

1

There's no such thing as a Nullable Byte Array, you can always set an Array to null.

As for the file upload, you might do it like the documentation for FileUpload.PostedFile suggests in the example.

UPDATE: Not sure how your DALC works but for passing the array to an stored procedure just make sure to pass DBNull.Value when the array is null.

UPDATE 2: You have to pass DBNull.Value to the procedure, for the DAL just set the array to null.

fileData = null;

Then when you call the procedure you have to check the property and either pass the value or DBNull.Value. See this question on how to do that.

edited May 23 '17 at 12:11

Community

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answered Mar 24 '12 at 17:39

shriek

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You say "nullable array of bytes", I say "array of nullable bytes". – Mr Lister Mar 24 '12 at 17:44
Gives Error "Cannot implicitly convert type 'System.DBNull' to 'byte[]' – IrishChieftain Mar 24 '12 at 18:37
Had to uncheck this as answer - does not answer how to handle the fact that an array of bytes cannot be null. Updating question. – IrishChieftain May 24 '12 at 11:05

IrishChieftain · Accepted Answer · 2012-06-11T16:18:18.650

0

The simple answer to this was to code four overrides for the DB Add method - which was what I was trying to avoid in the first place. Received no response showing a more elegant way to do this.

edited Jun 11 '12 at 16:18

answered May 26 '12 at 00:31

IrishChieftain

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How to Handle Non-Required File Upload Fields in DALC?

2 Answers2