Use VB.NET Manipulate Microsoft Access Database - vb.net

Question

How can I make this work?
Private Sub ListView_MouseClick(sender As Object, e As MouseEventArgs) Handles ListView.MouseClick
conndb = New OleDbConnection
conndb.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\Database1.accdb"
Try
conndb.Open()
Dim str As String
str = "Select * FROM customer WHERE CustomerID = '" & ListView.FocusedItem.Text & "'"
COMMAND = New OleDbCommand(str, conndb)
dr = COMMAND.ExecuteReader
If dr.Read = True Then
txtID.Text = dr("CustomerID")
txtFirstName.Text = dr("FirstName")
txtSurname.Text = dr("Surname")
txtAddress.Text = dr("Address")
txtCN1.Text = dr("ContactNo1")
txtCN2.Text = dr("ContactNo2")
txtEmail.Text = dr("EmailAddress")
txtRemarks.Text = dr("Remarks")
txtDebtStatus.Text = dr("DebtStatus")
txtDownPay.Text = dr("DownPayment")
txtDebtBal.Text = dr("DebtBal")
txtCustomerDate.Text = dr("Date")
End If
Catch ex As Exception
MessageBox.Show(ex.Message)
Finally
conndb.Dispose()
End Try
End Sub
I need help on how can I make this run without errors, Im using ms access as my database source. There seems to be an error using this code, this code works perfectly fine with mysql but in ms access, it says data mistype error or something like that. Need your help, thanks

Answer 1

Remove the ' surrounding the field CustomerID in your query :
str = "Select * FROM customer WHERE CustomerID = '" & ListView.FocusedItem.Text & "'"
becomes :
str = "Select * FROM customer WHERE CustomerID = " & ListView.FocusedItem.Text
MS Access sees a string when you put an apostrophe, so there is a Type Mismatch Exception, because it is expecting a number...
However, this is a pretty bad idea as Parametrized queries are a better way of doing this (see : Why should I create Parametrized Queries ?)
Also, Use Using
So all in all, it's just another brick in the wall :
Private Sub ListView_MouseClick(sender As Object, e As MouseEventArgs) Handles ListView.MouseClick
Using conndb As New OleDbConnection
conndb.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\Database1.accdb"
Try
conndb.Open()
Dim str As String
str = "Select * FROM customer WHERE CustomerID = #Customer"
Using COMMAND As New OleDbCommand(str, conndb)
COMMAND.Parameters.Add("#Customer", SqlDbType.Integer).Value = Integer.Parse(ListView.FocusedItem.Text)
dr = COMMAND.ExecuteReader
If dr.Read = True Then
txtID.Text = dr("CustomerID")
txtFirstName.Text = dr("FirstName")
txtSurname.Text = dr("Surname")
txtAddress.Text = dr("Address")
txtCN1.Text = dr("ContactNo1")
txtCN2.Text = dr("ContactNo2")
txtEmail.Text = dr("EmailAddress")
txtRemarks.Text = dr("Remarks")
txtDebtStatus.Text = dr("DebtStatus")
txtDownPay.Text = dr("DownPayment")
txtDebtBal.Text = dr("DebtBal")
txtCustomerDate.Text = dr("Date")
End If
End Using
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Using
End Sub

Answer 2

Take a look at this sample code that I put together a while back. You can probably learn a lot from this.
Private Sub TextBox1_TextChanged(sender As System.Object, e As System.EventArgs) Handles TextBox1.TextChanged, TextBox1.Click
Dim connectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Users\your_path\Desktop\Northwind_2012.mdb"
Dim selectCommand As String
Dim connection As New OleDbConnection(connectionString)
'selectCommand = "Select * From MyExcelTable where Fname = '" & TextBox1.Text & "'"
'"SELECT * FROM Customers WHERE Address LIKE '" & strAddressSearch & "%'"
'or ending with:
'"SELECT * FROM Customers WHERE Address LIKE '%" & strAddressSearch & "'"
selectCommand = "Select * From MyExcelTable where Fname Like '" & TextBox1.Text & "%'"
Me.dataAdapter = New OleDbDataAdapter(selectCommand, connection)
With DataGridView1
.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells
.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.ColumnHeader
.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.ColumnHeader
End With
Dim commandBuilder As New OleDbCommandBuilder(Me.dataAdapter)
Dim table As New DataTable()
table.Locale = System.Globalization.CultureInfo.InvariantCulture
Me.dataAdapter.Fill(table)
Me.bindingSource1.DataSource = table
Dim data As New DataSet()
data.Locale = System.Globalization.CultureInfo.InvariantCulture
DataGridView1.DataSource = Me.bindingSource1
Me.DataGridView1.AlternatingRowsDefaultCellStyle.BackColor = Color.Aqua
Me.DataGridView1.AutoResizeColumns( _
DataGridViewAutoSizeColumnsMode.AllCells)
End Sub