As we have discussed, the given code snippet will never keep
the stored image in the folder/disk space. We will also see both the read and
write operations here.
Dim img As Image
Private Sub imgFile_FileOk(ByVal sender As System.Object, _
ByVal e As System.ComponentModel.CancelEventArgs) _
img = Image.FromFile(imgFile.FileName)
btnSave.Enabled = True
picBox.Image = img
Catch ex As Exception
If InStr(UCase(ex.Message), UCase("Out of memory")) Then
MsgBox("Please select images only", _
MsgBoxStyle.OKOnly, "Error Occured")
The code snippet given above only displays the image
selected from the Dialog box in the picture box at UI. The code is written
inside the Try-Catch Block and, therefore, it also ensures the selection of
image files only.
Now let us have a look on the gist. The code given below is
actually inserting the image into the database in binary format.
Private Sub btnSave_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnSave.Click
Dim oConn As OleDb.OleDbConnection
Dim oComm As OleDb.OleDbCommand
Dim Err As String
Dim sInsertQuery As String
Dim FSO As New System.IO.FileStream(imgFile.FileName, _
sInsertQuery = "insert into images([image]) VALUES(?)"
oConn = New OleDb.OleDbConnection( _
oComm = New OleDb.OleDbCommand(sInsertQuery, oConn)
Dim imgArrayByte(CType(FSO.Length() - 1, Integer)) As Byte
FSO.Read(imgArrayByte, 0, imgArrayByte.Length)
Dim QueryParameter As New OleDb.OleDbParameter("@Picture", _
imgArrayByte.Length, ParameterDirection.Input, _
False, 0, 0, Nothing, DataRowVersion.Current, _
MsgBox("Image is saved successfully to the Database", _
btnSave.Enabled = False
Catch Ex As Exception
Err = Ex.Message
MsgBox("Error : " & Err, _
MsgBoxStyle.OKOnly, "Error Occured")
oConn = Nothing
oComm = Nothing
The code given above is actually inserting the images to the
Database. The above snippet needs a bit of clarification on some points, which
are given below.
One can see the variable sInsertQuery is initialized as “insert
into images([image]) VALUES(?).” The reason is that we can not write the
complete query here. We need to add a parameter, which will hold the image in
binary format, and this can only be done after converting the image to binary. (Obviously,
appending a parameter to the query cannot do this.)
For this reason we have used a placeholder [?] in the query
which is replaced by the "QueryParameter" afterwards.
Creating a new OleDB Parameter requires an array of bytes. For
that reason we have used a File System Object and created the array of bytes
out of it.
After successfully creating the parameter, it has replaced
the placeholder [?] in the query and the query gets executed.
Until now we were looking into the codes, which is actually
responsible for writing the images to the database. Now, let us look into the
section which is reading the images from the database.
Private Sub cmbImgIds_SelectedIndexChanged(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles cmbImgIds.SelectedIndexChanged
btnDelete.Enabled = False
Dim sQuery As New System.Text.StringBuilder()
Dim oDataTable As New DataTable()
Dim dtRow As DataRow
Dim imagedata() As Byte
Dim imageBytedata As MemoryStream
sQuery.Append("SELECT image FROM images WHERE imageId = " & _
oDataTable = New Connection().doDBconnection(sQuery.ToString, "Image")
For Each dtRow In oDataTable.Rows
btnDelete.Enabled = True
imagedata = dtRow.Item("image")
imageBytedata = New MemoryStream(imagedata)
picBox.Image = Image.FromStream(imageBytedata)
The above lines of codes are actually reading the image from
the database in binary format and then displaying it in the picture box at UI. A
few points from the above lines of code are discussed below.
One needs to import the System.IO in order to access
The Connection() is a user defined class that contains the
public function doDBconnection(). The public function takes the Query and a
proposed datatable name as input. After executing the query it returns the
results filled in a datatable with the proposed name.