How can I save multiple image (blob) from SQL table to image file by VB net?

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I am using vb net 2017.

By this next code i get request IMAGE from sql table (filed name MMOBJS.LNL_BLOB)

VB

     OpenConnection()

     cmd = New SqlCommand("Select badge.ID , emp.SSNO , emp.LASTNAME, emp.FIRSTNAME, emp.MIDNAME, BADGSTAT.NAME, DEPT.NAME , BADGE.ACTIVATE, BADGE.DEACTIVATE, MMOBJS.LNL_BLOB  FROM EMP INNER JOIN BADGE ON EMP.ID = BADGE.EMPID INNER JOIN UDFEMP ON UDFEMP.ID = EMP.ID INNER JOIN DEPT on UDFEMP.DEPT = DEPT.ID INNER JOIN BADGSTAT ON BADGE.STATUS = BADGSTAT.ID INNER JOIN MMOBJS ON MMOBJS.EMPID = BADGE.EMPID where BADGE.ID Like '" & DataGridView1.CurrentRow.Cells(0).Value.ToString & "%'", connections)
reader = cmd.ExecuteReader()

What I have tried:

and by next code, i can save one image for one selected record.

VB

If reader.Read = False Then
     MessageBox.Show("Фото для пропуска № " & DataGridView1.CurrentRow.Cells(0).Value.ToString & " нет в базе.", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information)
    Else

     'store image value from the database in byte
     Dim imageData As Byte() = reader(9)
     If Not imageData Is Nothing Then
         Using ms As New MemoryStream(imageData, 0, imageData.Length)
             ms.Write(imageData, 0, imageData.Length)
             pic_box.Image = Image.FromStream(ms, True)

             Dim Path As String = "C:\tmp2\"
             Dim Dir As String = System.IO.Path.GetDirectoryName(Path)

             Try
                 Try
                     If Not System.IO.Directory.Exists(Dir) Then
                         System.IO.Directory.CreateDirectory(Dir)
                     End If

                     With sfdpic
                         .Title = "Save image As"
                         .Filter = "Jpg, Jpeg Images|*.jpg; *.jpeg"
                         .AddExtension = True
                         .DefaultExt = ".jpg"
                         '.FileName = txt_ssno.Text + " " + txt_lname.Text + " " + txt_fname.Text + " " + txt_midname.Text
                         .FileName = DataGridView1.CurrentRow.Cells(1).Value.ToString + " " + DataGridView1.CurrentRow.Cells(2).Value.ToString + " " + DataGridView1.CurrentRow.Cells(3).Value.ToString + " " + DataGridView1.CurrentRow.Cells(4).Value.ToString
                         .OverwritePrompt = True
                         .InitialDirectory = Dir
                         .RestoreDirectory = True

                         If .ShowDialog = DialogResult.OK Then
                             If .FilterIndex = 1 Then
                                 pic_box.Image.Save(sfdpic.FileName, Imaging.ImageFormat.Jpeg)
                             End If
                         End If
                     End With

                 Catch ex As Exception
                     MessageBox.Show("Error: Saving Image Failed ->>" & ex.Message.ToString())

                 Finally
                     sfdpic.Dispose()
                 End Try

             Catch ex As Exception
                 Me.Cursor = Cursors.Default
                 MessageBox.Show(ex.Message, "Message", MessageBoxButtons.OK, MessageBoxIcon.Information)
             End Try

         End Using
     End If
     reader.Close()
     Cursor = Cursors.Default
 End If
 Cursor = Cursors.Default

 Try

I cannot save multiple image for filtered datagridview list. How can i do it?
Any example please.

Posted 13-Aug-18 4:28am

Roman Kuznetsov

Updated 13-Aug-18 10:11am

Patrice T

v3

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MadMyche · Accepted Answer · 2018-08-13T06:44:00

I noticed two errors right away.
Unfortunately VB is not my primary language and I do not have access to an IDE at the moment. You are going to need to work out any errors in syntax on your own.

Problem #1: Don't ever concatenate an SQL command together.
Use Parameterized queries to remove chances of SQL Injection
Fix: Change the WHERE clause

VB

' BAD:
     "...where BADGE.ID Like '" & DataGridView1.CurrentRow.Cells(0).Value.ToString & "%'"

' Good:
     "...where BADGE.ID = @BadgeID"
     cmd.Parameters.AddWithValue("@BadgeID", DataGridView1.CurrentRow.Cells(0).Value);

Problem #2: Only 1 value retrieved
Fix: Loop through the reader

VB

If reader.HasRows = False Then
	MessageBox.Show("Error Message")
Else
   While reader.Read()
      ' do your code here for each row in the reader object
   End While
End If