Question

我必须改进我的编码才能从VB连接到数据库，但它仍然不会让它一直暗示“ConnectionString属性尚未初始化”。

MessageBox.Show（“已发送订单”）

    provider = "Provider=Microsoft.Jet.OLEDB.12.0; Data Source="
    dataFile = "J:\Database511_be.accdb"
    myConnection.ConnectionString = connString
    myConnection.Open()>>>>>THIS IS THE SECTION THAT BUGS ME, IT WOULDN'T  CONNECT TO THE DATABASE
    Dim str As String


    str = "Insert INTO CUSTOMER_DATABASE([Items],[Pizza Size],[Quantity],[Table Number], [Total]) Values ( ?,?,?,?)"
    Dim cmd As OleDbCommand = New OleDbCommand(str, myConnection)

    cmd.Parameters.Add(New OleDbParameter("Items", CType(TextBox3.Text, String)))
    cmd.Parameters.Add(New OleDbParameter("Pizza Size", CType(TextBox4.Text, String)))
    cmd.Parameters.Add(New OleDbParameter("Quantity", CType(TextBox5.Text, String)))
    cmd.Parameters.Add(New OleDbParameter("Table Number", CType(ListBox4.Text, String)))
    cmd.Parameters.Add(New OleDbParameter("Total", CType(TextBox8.Text, String)))

    Try

        cmd.ExecuteNonQuery()
        cmd.Dispose()
        myConnection.Close()
        TextBox3.Clear()
        TextBox4.Clear()
        TextBox5.Clear()
        TextBox8.Clear()

    Catch ex As System.Exception


    End Try

Answer 1

您正在定义连接字符串，但未将其与OleDbConnection对象关联。你想这样做：

Using connection As New OleDbConnection(connString)
    connection.Open()
    ' ... do stuff with the open connection
End Using

或者，甚至更好

ApplicationConfig

ConnectionString属性尚未初始化

1 个答案: