MS Access参数化直通查询

Question

我在获取带有参数的查询以在要构建的MS Access DB中工作时遇到了一个小问题。 参数为数字形式时，我无法正确设置格式/语法。

这是代码：

Private Sub Command15_Click()
   Dim conn As ADODB.Connection
   Dim strConnection As String

   strConnection = "Driver={Microsoft ODBC for Oracle};Server=SERVER;Uid=USER_ID;Pwd=PASSWORD;"

   Set conn = New ADODB.Connection
   conn.Open strConnection
   conn.Execute " UPDATE L2000.DEPARTURE_STATUS DS " & _
              " SET DS.DEPARTURE_STATUS = '" & Forms!frmDepartureStatus.txtdeparturestatus & "' " & _
              " WHERE DS.DEPARTURE_NO = " & Forms!frmDepartureStatus.txtdepno
   conn.Close
   Set conn = Nothing
End Sub

通过参数从txtdepno发送的值是一个数字，我尝试了几种不走运的方法。

这是另一个类似的代码，但是这次参数是一个字符串：

Private Sub Command16_Click()
   Dim conn As ADODB.Connection
   Dim strConnection As String

   strConnection = "Driver={Microsoft ODBC for Oracle};Server=SERVER;Uid=USER_ID;Pwd=PASSWORD;"

   Set conn = New ADODB.Connection
   conn.Open strConnection
   conn.Execute " UPDATE L2000.USERS U " & _
            " SET U.STORER_ID = '" & Forms!EXAMPLE.txtInput2 & "'" & _
            " WHERE U.USER_ID = '" & Forms!EXAMPLE.txtInput & "'"
   conn.Close
   Set conn = Nothing
End Sub

Answer 1

字符串串联不是参数化。 但是，如果您使用字符串连接，则可以很轻松地解决此问题。 只需省略单引号，这样Oracle会将其视为数字。 用单引号将它们视为字符串：

Private Sub Command16_Click()
   Dim conn As ADODB.Connection
   Dim strConnection As String

   strConnection = "Driver={Microsoft ODBC for Oracle};Server=SERVER;Uid=USER_ID;Pwd=PASSWORD;"

   Set conn = New ADODB.Connection
   conn.Open strConnection
   conn.Execute " UPDATE L2000.USERS U " & _
            " SET U.STORER_ID = " & Forms!EXAMPLE.txtInput2  & _
            " WHERE U.USER_ID = " & Forms!EXAMPLE.txtInput 
   conn.Close
   Set conn = Nothing
End Sub

如果您确实想构建一个参数化查询，它将看起来像这样：

Private Sub Command16_Click()
   Dim conn As ADODB.Connection
   Dim strConnection As String

   strConnection = "Driver={Microsoft ODBC for Oracle};Server=SERVER;Uid=USER_ID;Pwd=PASSWORD;"

   Set conn = New ADODB.Connection
   conn.Open strConnection
   Dim cmd As New ADODB.Command
   Set cmd.ActiveConnection = conn
   cmd.CommandText =  "UPDATE L2000.USERS U " & _
            " SET U.STORER_ID = ?"
            " WHERE U.USER_ID = ?"
   cmd.Parameters.Append cmd.CreateParameter(, adInteger,adParamInput, 5, Forms!EXAMPLE.txtInput2 )
   cmd.Parameters.Append cmd.CreateParameter(, adInteger,adParamInput, 5, Forms!EXAMPLE.txtInput )
   cmd.Execute
   conn.Close
   Set conn = Nothing
End Sub