请问怎么从access数据库中读取图像
我从mdb中读取ole类型字段的图像，这个图像原来是用access加进去的。
代码如下：

<!--#include file= "conn.asp "-->
<%
if request( "id ") <> " " then
rid=int(request( "id "))
else
rid=1
end if
sql= "select top 1 id from [零售户] order by id desc "
set rs=conn.execute(sql)
maxid=int(rs( "id "))
sql= "select top 1 id from [零售户] order by id "
set rs=conn.execute(sql)
minid=int(rs( "id "))

if rid <1 then
rid=1
elseif rid> maxid then
response.redirect "?id= "&maxid
elseif rid <minid then
response.redirect "?id= "&minid
else
rid=rid
end if

sql= "select * from [零售户] where id= "&rid
Set rs=Server.CreateObject( "ADODB.Recordset ")
rs.Open sql,conn,1,1
Response.ContentType= "image/* "
dataSize=rs( "照片 ").actualSize
Response.BinaryWrite rs( "照片 ").getChunk(datasize)
response.End()
rs.close
set rs=nothing
call connclose()
%>

可是读出来只是红x啊。

[解决办法]
在ACCESS中使用了两个关键的技术来保存图形
1。使用了bmp格式
2。78个字节的文件头

<%
response.Expires = 0
response.Buffer = True
response.Clear
response.contentType = "image/bmp "
%>
接着你要干的就是去掉那78个字节的OLE对象的文件头。
<%
Const OLEHEADERSIZE = 78
nFieldSize = rs( "photo ").ActualSize
oleHeader = rs( "photo ").GetChunk(OLEHEADERSIZE)
imageBytes = rs( "photo ").GetChunk(nFieldSize - OLEHEADERSIZE)
Response.BinaryWrite imageBytes
%>

现在举一个例子：
如果你要得到一个职工的信息，这段信息包括一个介绍和他的图象。
并且要同时显示文字和图形。
代码如下：（其中的theImg是一个代理页面）
theImg.asp
<%
response.Expires = 0
response.Buffer = True
response.Clear
response.contentType = Session( "ImageType ")
response.BinaryWrite Session( "ImageBytes ")
Session( "ImageType ") = " "
Session( "ImageBytes ") = " "
response.End
%>


Function SetImageForDisplay(field, contentType)
OLEHEADERSIZE = 78
contentType = LCase(contentType)
select case contentType
case "gif ", "jpeg ", "bmp "
contentType = "image/ " & contentType
bytes = field.value
case "ole "
contentType = "image/bmp "
nFieldSize = field.ActualSize
oleHeader = field.GetChunk(OLEHEADERSIZE)
bytes = field.GetChunk(nFieldSize - OLEHEADERSIZE)
end select
Session( "imageBytes ") = bytes
Session( "imageType ") = contentType
End Function
'注意的是，程序中只使用了4中格式：gif, jpeg, bmp , ole .

<%
sql = "select * from Employees "
Set oRS = Server.CreateObject( "ADODB.Recordset ")
oRS.CursorLocation = 3
oRS.Open sql, "DSN=NW "
SetImageForDisplay oRS( "photo "), "ole "

Set oRS.ActiveConnection = Nothing
%>

要显示图象的话，只需要在另外一个asp中，假设为getEmpInfo.asp中
<img src= "theImg.asp "> </img>
[解决办法]
<img src= "showpic_riso_p.asp?id= <%=trim(rs( "id "))%> " width= "105 " height= "90 ">

showpic_riso_p.asp代码如下:
<%
Response.Buffer=true
Response.Clear
db= "gs.asp "
set conn=server.createobject( "adodb.connection ")
connstr= "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= " & Server.MapPath( " "&db& " ")
conn.open connstr

set iRe=server.createobject( "adodb.recordset ")
iSql= "select * from riso where id= "& Request( "id ") & " "

iRe.open iSql,conn,1,3
Response.ContentType=iRe( "type ")
Response.BinaryWrite iRe( "img ")

iRe.close
set iRe=Nothing
%>