Attempting to insert picture into sql database - mysql

Question

I want to insert an image into my SQL database. I have this code currently and it is entering a Null where the image should be. Why is this occurring?
I'm using here a simple addquestion Class.
You can find the code I used bellow :
Imports System.IO
Imports System.Data.SqlClient
Public Class addquestion
Dim con As New System.Data.Odbc.OdbcConnection("DRIVER={MySQL ODBC 5.2 ANSI Driver};SERVER=localhost;PORT=3306;DATABASE=physicsapp;USER=root;PASSWORD=root;OPTION=3;")
Dim rs As Odbc.OdbcDataReader
Private Sub addquestion_Load(sender As Object, e As EventArgs) Handles MyBase.Load
End Sub
Private Sub QuestionButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles QuestionButton.Click
Dim myFileDlog As New OpenFileDialog
myFileDlog.InitialDirectory = "c:/"
myFileDlog.Filter = "All Files (*.*)|*.*" & _"|Picture Files (*.png)|*.png"
myFileDlog.FilterIndex = 1
myFileDlog.RestoreDirectory = True
If myFileDlog.ShowDialog() = _
DialogResult.OK Then
If Dir(myFileDlog.FileName) <> "" Then
MsgBox("File Exists: " & _
myFileDlog.FileName, _
MsgBoxStyle.Information)
Else
MsgBox("File Not Found", _
MsgBoxStyle.Critical)
End If
End If
qnametextbox.Text = myFileDlog.FileName
End Sub
Dim ans as Char = "B"
Dim file As String = qnametextbox.Text
Dim question As Image
question = Image.FromFile(file)
Dim ms As New MemoryStream()
question.Save(ms, System.Drawing.Imaging.ImageFormat.Png)
Dim data As Byte() = ms.GetBuffer()
Dim s As String = "INSERT INTO tests VALUES (#Question ,'" & ans & "', 200)"
Dim sql As New Odbc.OdbcCommand(s, con)
sql.Parameters.Add("#Question", Odbc.OdbcType.VarBinary).Value = data
con.Open()
sql.ExecuteNonQuery()
con.Close()
this is the definition of the table
CREATE TABLE `tests` (
`Question` blob NOT NULL,
`CorrectAnswer` varchar(8) DEFAULT NULL,
`QuestionNumber` int(8) NOT NULL AUTO_INCREMENT,
KEY `QuestionNumber` (`QuestionNumber`)
) ENGINE=MyISAM AUTO_INCREMENT=201 DEFAULT CHARSET=utf8
Any suggestion can help.
Thanks.

Answer 1

Regardless of what data access technology or database you use, you need to convert am Image to a Byte first and then save that. On retrieval, you convert the Byte array back to an Image.
To save:
Dim connection As New SqlConnection("connection string here")
Dim command As New SqlCommand("UPDATE MyTable SET Picture = #Picture WHERE ID = 1", connection)
'Create an Image object.'
Using picture As Image = Image.FromFile("file path here")
'Create an empty stream in memory.'
Using stream As New IO.MemoryStream
'Fill the stream with the binary data from the Image.'
picture.Save(stream, Imaging.ImageFormat.Jpeg)
'Get an array of Bytes from the stream and assign to the parameter.'
command.Parameters.Add("#Picture", SqlDbType.VarBinary).Value = stream.GetBuffer()
End Using
End Using
connection.Open()
command.ExecuteNonQuery()
connection.Close()