使用VB.NET写入MS-Access数据库问题

Question

I'm utilizing VB.Net to try and write to a database I created (the machine that needs to be writing to the database is the owner of the database, so there should be no permission issues). I'm getting no errors on when my subs for writing to the database are run, but no new records are created in my database. I'm successfully connected to the database, as my subs for returning records work perfectly.

The Sub for writing to the database:

Public Sub LogThisCard(a As Object)
    Dim con As New OleDb.OleDbConnection
    Dim da As New OleDb.OleDbDataAdapter
    Dim sql As New OleDb.OleDbCommand
    Dim inMachine As String = "Yes"

    con.ConnectionString = Connection()
    con.Open()

    Try
        sql.Connection = con
        sql.CommandText = "INSERT INTO LogTable (MSA, Foo, Bar, Jack, Rabbit, Date_/_Time, Foxtrot) VALUES (@MSA, @Foo, @Bar, @Jack, @Rabbit, @DT, @Foxtrot)"

        sql.Parameters.AddWithValue("MSA", a.MSA)
        sql.Parameters.AddWithValue("Foo", a.Foo)
        sql.Parameters.AddWithValue("Bar", a.Bar)
        sql.Parameters.AddWithValue("Jack", a.Jack)
        sql.Parameters.AddWithValue("Rabbit", a.Rabbit)
        sql.Parameters.AddWithValue("DT", DateTime.Now())
        sql.Parameters.AddWithValue("Foxtrot", a.FoxTrot)

        da.InsertCommand = sql
        da.InsertCommand.ExecuteNonQuery()
    Catch ex As Exception
        Debug.Print(ex.ToString)
    End Try

    con.Close()
End Sub

The Database Design is as follows:

• ID: AutoNumber (Primary Key)
• MSA: Number
• Foo: Number
• Bar: Short Text
• Jack: Short Text
• Rabbit: Short Text
• Date / Time:Date/Time
• Foxtrot: Short Text

Answer 1

It could be an issue with Access and your DateTime Parameter. If DateTime allows null values, change your insert to do all except DateTime. If the Insert works then you know the issue.

I am not sure why access has issue with addwithvalue, but I see it often. I have found it better to declare a variable of parameter and set properties then add the param when it comes to date times.

Example:

Dim cmd As OleDb.OleDbCommand
Dim param As New OleDb.OleDbParameter
param.Direction = ParameterDirection.Input
param.DbType = DbType.Date
param.Value = Date.Now

cmd.Parameters.Add(param)