更新访问错误

Question

    Dim conn As OleDbConnection
    Dim cmd As OleDbCommand

    Public Sub openDB()
        conn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & Application.StartupPath & "\VFMS_DB.mdb;" & "Jet OLEDB:System Database=Security.mdw;User ID=Adster;Password=300624;")
        conn.Open()
    End Sub

    Public Function UpdateUser() As Integer
        Dim retCode As New Integer

        Try
            openDB()
            cmd = conn.CreateCommand()

下面的更新命令不断给我这个错误：“从字符串转换”“WHERE [用户名] =”“键入‘双’无效”。我不知道为什么。该aUserName字段是一个字符串领域，我检查，以确保它的填充。

            cmd.CommandText = "UPDATE Users SET [First Name] = '" & aName & "', [Last Name] = '" & aSurname & "', [Contact Number] = '" & aContactNum & "', [Password] = '" & aPassword & "', [User Rights] = '" & aUserRights + "' WHERE [Username] = '" + aUserName + "' "

            cmd.ExecuteNonQuery()
            conn.Close()

            'rsAddRecs = rsConn.Execute("UPDATE Users ([First Name], [Last Name], [Contact Number], [User Name], [Password], [User Rights]) VALUES ('" & aName & "','" & aSurname & "','" & aContactNum & "','" & aUserName & "','" & aPassword & "','" & aUserRights & "')")

            retCode = 0
            'rsConn.Close()
            Return retCode

        Catch ex As Exception
            MessageBox.Show(ex.ToString, ex.Message, MessageBoxButtons.OK)
            retCode = 1
            Return retCode
        End Try
    End Function

Answer 1

您有一个错字。您使用的 + 是在SQL字符串代替的端部的concat字符的＆字符

<强>错误

cmd.CommandText = "UPDATE Users SET [First Name] = '" & aName & _ 
                  "', [Last Name] = '" & aSurname & _
                  "', [Contact Number] = '" & aContactNum & _
                  "', [Password] = '" & aPassword & "', [User Rights] = '" & _
                  aUserRights + "' WHERE [Username] = '" + aUserName + "' "
'                             ^                          ^           ^

从右

cmd.CommandText = "UPDATE Users SET [First Name] = '" & aName & _
                  "', [Last Name] = '" & aSurname & _
                  "', [Contact Number] = '" & aContactNum & _
                  "', [Password] = '" & aPassword & "', [User Rights] = '" & _
                  aUserRights & "' WHERE [Username] = '" & aUserName & "' "
'                             ^                          ^           ^

Answer 2

您SQL代码使用[Username]：

cmd.CommandText = "UPDATE Users SET ... [Username]...

尽管你注释的代码中使用[User Name]：

'rsAddRecs = rsConn.Execute("UPDATE Users ... [User Name]...

可能错误的列名是问题的根源？

另一种思考：有你如消毒您的参数值可以在值包含被打乱动态SQL单引号。在任何情况下，我想你应该考虑使用准备好的语句（甚至是程序），并使用参数对象调用SQL，从而推迟参数值的OLE DB提供程序的消毒，这当然会知道更多关于主题比你或I：）