GetBytes() issue - attemting to load into a MemoryStream object

Hi all,

I have a column in my database that is of type image (bytes) and what to load this data into a System.IO.MemoryStream object but can't seem to find out how to do it. Hopefully, someone out there would have had experience of doing this and can show me the way. I have the following code...

System.IO.MemoryStream stream = new System.IO.MemoryStream(objSqlCeDataReader.GetBytes(0, 0, null, 0, int.MaxValue));

...which I know is wrong as I think this call to GetBytes() only returns the size/length of the total bytes as I am passing in a null buffer (3rd param). How can I do the database call and pass it into the MemoryStream object in one scoop

Thanks

.NET Development1

Hi,

Take a look at this article for sample code:
http://www.codeproject.com/cs/database/images2db.asp

Charles

I have written a couple of tutorials on the subject:

Saving and Retrieving Images From SQL Server Using DAAB

Saving and Displaying Photos in SQL Server using ASP.NET and FileUpload Control

Here is a snippet of code:

private Image RetrieveImage(int photoId)
{
Image image = null;

using (SqlConnection connection = new SqlConnection("..."))
{
using (SqlCommand command = connection.CreateCommand())
{
command.CommandText = "SELECT Photo FROM Photos
";
command.Parameters.AddWithValue(" ", photoId);

connection.Open();
byte[] imageData = (byte[])command.ExecuteScalar();

MemoryStream memStream = new MemoryStream(imageData);
image = Image.FromStream(memStream);
}
}

return image;
}

Regards,

Dave

And to include the minimal change from the original, non-working snippet (this assumes the type is Binary, VarBinary, Image or Timestamp in order to return a byte array from GetValue):

System.IO.MemoryStream stream = newSystem.IO.MemoryStream((byte[])objSqlCeDataReader.GetValue(0));

Alternatively, if you want this to work with other types that don't return byte arrays by default, but that work with GetBytes():

byte[] buffer = new byte[objSqlCeDataReader.GetBytes(0, 0, null, 0, int.MaxValue)];
long length = objSqlCeDataReader.GetBytes(0, 0, buffer, 0, buffer.Length);
System.IO.MemoryStream stream = newSystem.IO.MemoryStream(buffer, 0, length);

ok - thanks for the feedback, guys!