Executing an SQL query in an Access Database in VB.NET

Question

I have already posted one question about this piece of code before lol. But now I am having a different problem and need help with it. Basically this is code for a search button on a Windows Form coded in VB.NET.

Private Sub SearchButton_Click(sender As Object, e As EventArgs) Handles SearchButton.Click
    Dim cnnOLEDB As New OleDbConnection
    Dim cmdOLEDB As New OleDbCommand
    Dim strConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & System.Environment.CurrentDirectory & "\All Keyed Up, Lock & Safe, LLC.accdb"
    cnnOLEDB.ConnectionString = strConnectionString
    cnnOLEDB.Open()
    Dim Connection As New SqlClient.SqlConnectionStringBuilder
    Connection.DataSource = "file:///C:\Users\thelukester145\Documents\All%20Keyed%20Up\All%20Keyed%20Up,%20Lock%20&%20Safe,%20LLC.accdb"
    Dim objSQLConnection = New SqlClient.SqlConnection(Connection.ConnectionString)
    Dim cmd As New SqlCommand()
    Dim myTable As New DataTable()

    Dim SearchFor = SearchBox.Text
    If AddressButton.Checked Then
        cmd.Connection = objSQLConnection
        cmd.CommandText = "SELECT * FROM [McDonald's-Corporate Stores] WHERE [Address] LIKE '%" & SearchFor & "%'"
        Dim myAdapter As New SqlDataAdapter(cmd)
        myAdapter.Fill(myTable)
        DataGrid.DataGridView1.DataSource = myTable
    ElseIf NumberButton.Checked Then
        cmd.Connection = objSQLConnection
        cmd.CommandText = "SELECT * FROM [McDonald's-Corporate Stores] WHERE [McOpCo#] LIKE '%" & SearchFor & "%'"
        Dim myAdapter As New SqlDataAdapter(cmd)
        myAdapter.Fill(myTable)
        DataGrid.DataGridView1.DataSource = myTable
    End If
    DataGrid.Show()
    cnnOLEDB.Close()


End Sub

The database that is attempting to be searched is a database of customers for our family buisness. I am trying to search by either the address or store number of our customer. I've worked through who knows how many fatal errors but the newest one has me sort of stumped. It is crashing on myAdapter.Fill(myTable). The error message it gives is this:

An unhandled exception of type 'System.Data.SqlClient.SqlException' occurred in System.Data.dll

Additional information: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 25 - Connection string is not valid)

Any help would be much appreciated :)

Answer 1

Well, you are freely mixin OleDb classes with SqlClient classes. The two are for different database types. OleDb is needed for Access, SqlClient classes are used for Sql Server.

So you need to change all the classes SqlCommand, SqlCommandBuilder, SqlDataAdapter,SqlConnectionStringBuilder with the corresponding classes OleDbCommand, OleDbCommandBuilder, OleDbDataAdapter, OleDbConnectionStringBuilder

Infact, the error message is emitted by the SqlClient library that tries to use your connection string as it was a connectionstring for an SQL Server database and, of course, it fails to find it.

Also, I am not sure about that, but probably the DataSource property doesn't need the prefix file:/// and the Encoding of spaces with %20