在C＃中检索SQL Server中的二进制字段

Question

I want to save a pdf file in a varbinary(MAX) type column, and I use a TableAdapter in SQL Server. I wrote this code to insert:

DataSet1TableAdapters.Table1TableAdapter tblpdf = new DataSet1TableAdapters.Table1TableAdapter();

byte[] b = System.IO.File.ReadAllBytes(pdfDocument1.FilePath);
tblpdf.InsertQuery(b);

and it works correctly, but I have a problem retrieving the PDF fro the binary column. I use this code:

byte[] c= (byte[]) table1TableAdapter.ScalarQuery(txtSearch.Text); //with txtsearch box i search a field

System.IO.File.WriteAllBytes(pdfDocument1.FilePath, c);

and I get an error

the path could not be null

and I think it means that my "c" variable is null and ScalarQuery does not work correctly.

Please help me

Answer 1

@MarcB: Yes, you are right, i change this line:

System.IO.File.WriteAllBytes(pdfDocument1.FilePath, c);

to this one:

System.IO.File.WriteAllBytes(@"D:\\serah.pdf", c);

and it works correctly.

but now the question is how can i use "WriteAllBytes" to write c into a variable in the code, actually i want to do something like this:

System.IO.File.WriteAllBytes(ff, c);

pdfDocument1.FilePath = ff;