ASP判断数据库值是否为空的通用函数

由于各种字段属性不同，判断字段是否为空的方法也各异．

下面是一个通用函数，免去了还要看字段类型之苦．

check a variable isnt "empty"
function isblank(byref tempvar)
by default, assume its not blank
isblank = false
now check by variable type
select case vartype(tempvar)
empty & null
case 0, 1
isblank = true
string
case 8
if len(tempvar) = 0 then
isblank = true
end if
object
case 9
tmptype = typename(tempvar)
if (tmptype = "nothing") or (tmptype = "empty") then
isblank = true
end if
array
case 8192, 8204, 8209
does it have at least one element?
if ubound(tempvar) = -1 then
isblank = true
end if
end select
end function

应用实例：

if isblank(rs("upic")) then
  upicurl="/images/nonepic.jpg"
 else
  upicurl=rs("upic")
 end if