创建断开连接的ADO记录集时出错

Question

我试图创建一个包含备注字段（adLongVarWChar）的ADO断开连接的记录集。 出于某种原因它被转换回adVarWChar。 我在做什么错？

Private Sub Form_Load() 
Dim rs As New Recordset 

    rs.Fields.Append "test", adLongVarWChar, 512, adFldIsNullable Or adFldLong Or adFldMayBeNull Or adFldMayDefer Or adFldUnknownUpdatable 
    Debug.Print rs.Fields(0).Type & " <- This should be 203 (adLongVarWChar) but it returns 202 (adVarWChar)" 

    Unload Me 
End Sub 

Answer 1

事实证明，出于某种原因，你需要首先添加一条记录，然后将数据类型正确返回：

Private Sub Form_Load() 
Dim rs As New Recordset 

    rs.Fields.Append "test", adLongVarWChar, &H7FFFFFFF, adFldIsNullable Or adFldLong Or adFldMayBeNull Or adFldMayDefer Or adFldUnknownUpdatable 
    Debug.Print rs.Fields(0).Type & " <- This should be 203 (adLongVarWChar) but it returns 202 (adVarWChar)" 
    rs.Open 
    rs.AddNew 
    rs.Update 
    Debug.Print rs.Fields(0).Type & " <- This is now 203 (adLongVarWChar)" 

    Unload Me 
End Sub