Question

I have done this previously but in a different way. I am trying to get the code below to work. If I do not cast ‘OriginalPhoto’ or ‘Thumbnail’ an error occurs. Implicit conversion from data type varchar to varbinary(max) is not allowed. Use the CONVERT function to run this query. I don’t understand why it asking to cast. However if I do cast it, the images add to the database just fine in a binary data format. When trying to view the images, i get the error ‘Unable to display the given data’. I have inserted both byte[] into a table using a SqlDataAdapter and that works. I want to use this method though, what am I doing wrong?

PROFILEGALLERY TABLE CONTAINS:

UserId nvarchar(50)
Title nvarchar(10)
OriginalImage varbinary(max)
ThumbImage varbinary(max)

protected void AddPhotoToDatabase() {     byte[] OriginalPhoto = GetImage();     byte[] Thumbnail = GenerateThumbnail();     string Title = FileUpload1.FileName.ToString();     string sql = 'INSERT INTO [ProfileGallery] ([UserId], [Title], [OriginalImage], [ThumbImage]) VALUES ('' + User.Identity.Name + '', '' + Title + '', CAST('' + OriginalPhoto + ''AS VARBINARY(MAX)), CAST('' + Thumbnail + ''AS VARBINARY(MAX)))';     string strCon = System.Web.Configuration.WebConfigurationManager.ConnectionStrings['SocialSiteConnectionString'].ConnectionString;     SqlConnection conn = new SqlConnection(strCon);     SqlCommand comm = new SqlCommand(sql, conn);     conn.Open();     comm.ExecuteNonQuery();     conn.Close(); }  protected byte[] GetImage() {     byte[] photo = new byte[FileUpload1.PostedFile.ContentLength];     FileUpload1.PostedFile.InputStream.Read(photo, 0, photo.Length);     return photo; }  protected byte[] GenerateThumbnail() {     System.Drawing.Image image = System.Drawing.Image.FromStream(FileUpload1.PostedFile.InputStream);     double thumbwidth = 0;     double thumbheight = 0;     double imgsz = 150.0;     if (imgsz / image.Width < imgsz / image.Height)     {         thumbwidth = image.Width * (imgsz / image.Width);         thumbheight = image.Height * (imgsz / image.Width);     }     else     {         thumbwidth = image.Width * (imgsz / image.Height);         thumbheight = image.Height * (imgsz / image.Height);     }     System.Drawing.Image thumb = image.GetThumbnailImage((int)thumbwidth, (int)thumbheight, delegate() { return false; }, (IntPtr)0);     MemoryStream ms = new MemoryStream();     thumb.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);     return ms.ToArray(); } 

Answer 1

You should use sql parameters:

using( SqlConnection cnn = GetConnection() ) {     using( SqlCommand cmd = cnn.CreateCommand() ) {         cmd.CommandText = 'INSERT INTO [ProfileGallery] ([UserId], [Title], [OriginalImage], [ThumbImage]) VALUES (@UserId, @Title, @OriginalPhoto, @Thumbnail)';         cmd.Parameters.AddWithValue( '@UserId', User.Identity.Name );         cmd.Parameters.AddWithValue( '@Title', Title );         cmd.Parameters.AddWithValue( '@OriginalPhoto', OriginalPhoto );         cmd.Parameters.AddWithValue( '@Thumbnail', Thumbnail );          cnn.Open();         cmd.ExecuteNonQuery();         cnn.Close();     } }