急！大家帮忙看看！

[bluesanke]

Private Sub Form_Load()
Command1.Enabled = False
Command2.Enabled = False
Command3.Enabled = True
Command4.Enabled = True
TableInit
Mycn.Open "Provider=OraOLEDB.Oracle.1;Persist Security Info=False;PassWord=dytd;User ID=dytd;Data Source=dytd"
Myrs1.CursorLocation = adUseClient
Myrs1.Open "select distinct XZZ_TBDW from XZ_ZHGL_GTZYGLGBPXB ", Mycn
If Myrs1.RecordCount >= 1 Then
While Myrs1.EOF = False
Combo1.AddItem Myrs1.Fields(0)
Myrs1.MoveNext
Wend
Combo1.ListIndex = 0
Myrs1.Close
Else
MsgBox "仓库中目前无余额信息，请添加进库信息后再试！", vbOKOnly + vbExclamation, "警告"
Exit Sub
End If
End Sub
为什么有时运行到《Combo1.AddItem Myrs1.Fields(0)》这句的时候会说实施错误94，无效使用Null，各位大哥这是怎么回事，该怎么改呀！

[cjwcyc]

因为表字段值为Null
代码改为
if isnull(Myrs1.Fields(0))=faluse then
Combo1.AddItem Myrs1.Fields(0)
endif

[rappercn]

改成：Combo1.AddItem Myrs1.Fields(0) & ""

就可以了

[bluesanke]

谢谢搞定了，能解释为什么吗？！：）