大师:好!请问如何避免如下代码错误?
For Each a1 As String In mxkm
If filter = "" Then
filter = "dttzflmxb33 like '" & a1 & "*'"
Else
filter = filter & " or dttzflmxb33 like '" & a1 & "*'"
End If
Next
jfje = DataTables("dttzflmxb").Compute("sum(dttzflmxb6)"," dttzflmxb33 is not null" & " and (" & filter & ")" )
当filter为空时,就会出现错误。如果不想通过判断filter是否为空,如何改写上面的红色部分代码?