图片数据的存与取示例

图片数据存入数据库：
        sqlstr="select * from "&tbname&" where id is null"
        set rs=server.createobject("adodb.recordset")
        rs.Open sqlstr,conn,1,3
        rs.AddNew ()
        rs("title")=title
        rs("filename")=filename
        rs("filetype")=filetype
        rs("thelevel")=thelevel
        rs("uploaddate")=date()
        rs("uploadip")=request.ServerVariables("REMOTE_ADDR")
        rs("contenttype")=contenttype
        rs("data").AppendChunk (binstr)
        rs("size")=size
        rs("offset")=offset
        rs.Update
        rs.Close()

读取显示：
    rs.Open sqlstr,conn,3
    if not rs.EOF then
            contenttype=rs("contenttype")
            binstr=rs("data").GetChunk(rs("size")+rs("offset"))
            if rs("offset")=1 then
                binstr=midb(binstr,2)
            end if
            if instr(contenttype,"text/")=1 or _
               instr(contenttype,"image/")=1 or _
               instr(contenttype,"application/msword")=1 then
                response.contenttype=trim(contenttype)
                response.binarywrite binstr
            else
                response.addheader "Content-Disposition","attachment;filename="""&rs("filename")&""""
                response.contenttype=trim(contenttype)
                response.binarywrite binstr
            end if
            if request("preview")<>"yes" then
                sqlstr="update "&tbname&" set downtimes=downtimes+1 where id="&fileid
                conn.Execute sqlstr
            end if
    end if
说明：
对于超长的二进制数据（如图像数据）要使用fieldname.AppendChunk() 和fieldname.GetChunk()来读写。

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