Visual Basic .NET Access Database Record Add - database

Question

I have problem with database save changes:
coon1.ConnectionString = _
"Provider=Microsoft.Jet.OLEDB.4.0;Data source=" & _
"magazyn.mdb"
sql = "INSERT INTO magazyn (ID_Towaru,Kod_Towaru,Nazwa_Towaru,Ilość_w_magazynie,ilość_minimalna,ALERT) VALUES ('" & jakiid & "','" & kodtowaru & "','" & nazwatowaru & "','" & iloscwmagazynie & "','" & iloscminimalna & "',0)"
Dim MyConnection As New OleDbConnection(conn)
Dim command1 As New OleDbCommand(sql, MyConnection)
command1.Connection.Open()
command1.ExecuteNonQuery()
MyConnection.Close()
I try add new record to table magazyn, but when opened database with Access then I didn't see any new record related to magazyn in the table. But ViewGrid shows me this new element until I close and re-open the program.
Does someone know where the problem is?

Answer 1

Always use parameters and not string concatenation. This rule should be followed categorically
sql = "INSERT INTO magazyn " +
"(Kod_Towaru,Nazwa_Towaru,Ilość_w_magazynie,ilość_minimalna,ALERT) " +
"VALUES (?, ?, ?, ?,0)"
Using MyConnection As New OleDbConnection(conn)
Using command1 As New OleDbCommand(sql, MyConnection)
command1.Connection.Open()
command1.Parameters.AddWithValue("#Kod", kodtowaru)
command1.Parameters.AddWithValue("#naz", nazwatowaru)
command1.Parameters.AddWithValue("#ilo", iloscwmagazynie)
command1.Parameters.AddWithValue("#mini", iloscminimalna)
command1.ExecuteNonQuery()
End Using
End Using
This, of course, requires that the variables used as value for the parameters are of the correct datatype.

Answer 2

Please Insert This Below Coding in Module.
Imports System.Data.OleDb
Module Module1
Public OleCn As New OleDbConnection()
Public Function StrConnection() As String
StrConnection = "Provider=Microsoft.Ace.Oledb.12.0; Data Source=" & My.Application.Info.DirectoryPath.ToString() & "\BackUp\Testing.Accdb;"
Return StrConnection
End Function
After This Insert the Below Coding in Save Button.
Dim msg As DialogResult = MessageBox.Show("Do you want to Save this Record? ", "Response", MessageBoxButtons.YesNo, MessageBoxIcon.Question)
If (msg = vbYes) Then
If RequiredEntry() = True Then
Return
End If
Try
With OleCn
If .State <> ConnectionState.Open Then
.ConnectionString = StrConnection()
.Open()
End If
End With
Catch ex As Exception
MessageBox.Show(ex.Message, "Connection Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
Try
Dim sSQL As String = "insert into Vendor values(#VendorCode,#VendorName,#Address,#City,#LandPhone,#Mobile,#EmailID,#Balance)"
Dim cmd As OleDbCommand = New OleDbCommand(sSQL, OleCn)
'VendorCode
Dim VendorCode As OleDbParameter = New OleDbParameter("#VendorCode", OleDbType.VarChar, 10)
VendorCode.Value = txtVendorCode.Text.ToString()
cmd.Parameters.Add(VendorCode)
'VendorName
Dim VendorName As OleDbParameter = New OleDbParameter("#VendorName", OleDbType.VarChar, 25)
VendorName.Value = txtVendorName.Text.ToString()
cmd.Parameters.Add(VendorName)
'Address
Dim Address As OleDbParameter = New OleDbParameter("#Address", OleDbType.VarChar, 50)
Address.Value = txtAddress.Text.ToString()
cmd.Parameters.Add(Address)
'City
Dim City As OleDbParameter = New OleDbParameter("#City", OleDbType.VarChar, 25)
City.Value = txtCity.Text.ToString()
cmd.Parameters.Add(City)
'LandPhone
Dim LandPhone As OleDbParameter = New OleDbParameter("#LandPhone", OleDbType.VarChar, 50)
LandPhone.Value = txtLandPhone.Text.ToString()
cmd.Parameters.Add(LandPhone)
'Mobile
Dim Mobile As OleDbParameter = New OleDbParameter("#Mobile", OleDbType.VarChar, 15)
Mobile.Value = txtMobile.Text.ToString()
cmd.Parameters.Add(Mobile)
'EmailID
Dim EmailID As OleDbParameter = New OleDbParameter("#EmailID", OleDbType.VarWChar, 25)
EmailID.Value = txtEmailID.Text.ToString()
cmd.Parameters.Add(EmailID)
'Balance
Dim Balance As OleDbParameter = New OleDbParameter("#Balance", OleDbType.VarWChar, 10)
Balance.Value = txtBalance.Text.ToString()
cmd.Parameters.Add(Balance)
If cmd.ExecuteNonQuery() Then
OleCn.Close()
MessageBox.Show("New Record is Added Successfully.", "Record Saved")
Call clear()
Else
MsgBox("Record Addition Failed ", MsgBoxStyle.Critical, "Addition Failed")
Return
End If
Catch ex As Exception
MessageBox.Show(ex.Message.ToString(), "Data Error")
Exit Sub
End Try
End If