User-1994446809 posted
I have a code behind a web form that is suppose to store image into the database;
protected void Button1_Click(object sender, EventArgs e)
{
// Read the file and convert it to Byte Array
string filePath = FileUpload1.PostedFile.FileName;
string filename = Path.GetFileName(filePath);
string ext = Path.GetExtension(filename);
string contenttype = string.Empty;
int size = FileUpload1.FileBytes.Length;
//Set the contenttype
if (ext == ".jpg")
{
contenttype = "image/jpg";
}
if (contenttype != string.Empty)
{
Stream fs = FileUpload1.PostedFile.InputStream;
BinaryReader br = new BinaryReader(fs);
Byte[] bytes = br.ReadBytes((Int32)fs.Length);
//insert the file into database
string sql = "INSERT INTO DocTbl(Name, Contyp,Size, CardData)" +
" VALUES(@Name, @ContentType,@Size, @CardData);SELECT @@IDENTITY";
SqlParameter[] parameters = new[]
{
new SqlParameter("@Name",filename ),
new SqlParameter("@ContentType",contenttype ),
new SqlParameter("@Size",size ),
new SqlParameter("@CardData",bytes )
};
int id = ExecuteScalar(sql, parameters);
Session["CardId"] = id;
if (id != -1)
{
lblMessage.ForeColor = System.Drawing.Color.Green;
lblMessage.Text = "File Uploaded Successfully";
// Return a QR pic
BindDocQR();
}
else
{
lblMessage.ForeColor = System.Drawing.Color.Red;
lblMessage.Text = "File Uploaded Failed";
}
}
And in my Database Table, I have four columns, namely:
Id, Name, Contyp, Size, CardData.
| Id |
Name |
Contyp |
Size |
CardData |
The data type of these columns are set as nvarchar(MAX). When I try to upload any image, it tells me "File Uploaded Failed". I tried to resolve this by removing the "Id" column from the table, in order to match with the parameters and I got this error
in the browser;
Exception Details: System.InvalidCastException: Object cannot be cast from DBNull to other types.
Source Error:
Line 175: if (obj != null)
Line 176: {
Line 177: result = Convert.ToInt32(obj);
Line 178: }
Line 179: }
|
When i got this error, I tried to set the columns to "Allow Nulls", but it did not work. I have also tried to set the Data Type of "Contyp" column to varbinary(MAX) to see if this was the problem but it did not work too.
What should I do please?
