这个问题已经不是什么新鲜问题了，网上也有大把的教程，但大多数是授人以鱼，而不授人以渔，经过辛苦的资料收集，思考，调试，整理，我基本上已经把这个问题从原理上搞清楚了，现在根据我自己的理解，在范例程序的基础上，加以解释，希望能对部分网友有所帮助。
请诸位大虾能对其中的不正或不良这处予以指正。
我想循序渐进，先讲一个简单的，单个图片文件保存到数据库。
这个范例共包括三个ＡＳＰ文件和一个数据库（一个表），全部在同一目录下。
１、tblImage 表结构（ACCESS 2000）
sn 自动编号 序列号
content-type 文本 图片类型
image OLE 对象 图片数据
２、SimpleImageToData.asp：上传表单及保存图片到数据库的代码部分，主要文件。
<%@ Language=VBScript %>
<% option explicit %>
<%
'从一个完整路径中析出文件名称
function getFileNamefromPath(strPath)
getFileNamefromPath = mid(strPath,instrrev(strPath,"\")+1)
end function
'定义数据库连接字符串
dim cnstr
cnstr = "driver={Microsoft Access Driver (*.mdb)};dbq=" & server.MapPath("./upload.mdb")
%>
<HTML>
<HEAD>
<title>单个图像保存到数据库</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
</HEAD>
<body>
<p><a href="SimpleImageToData.asp">上传图片</a>
<a href="ShowImageListFromData.asp">显示图片</a><hr></p>
<%
if request.ServerVariables("REQUEST_METHOD") = "POST" then
dim sCome, sGo, binData, strData
dim posB, posE, posSB, posSE
dim binCrlf
dim strPath, strFileName, strContentType
binCrlf = chrb(13)&chrb(10) '定义一个单字节的回车换行符
set sCome = server.CreateObject("adodb.stream")
sCome.Type = 1 '指定返回数据类型 adTypeBinary=1,adTypeText=2
sCome.Mode = 3 '指定打开模式 adModeRead=1,adModeWrite=2,adModeReadWrite=3
sCome.Open
sCome.Write request.BinaryRead(request.TotalBytes)
sCome.Position = 0
binData = sCome.Read
'response.BinaryWrite binData '调试用：显示提交的所有数据
'response.Write "<hr>" '调试用
set sGo = server.CreateObject("adodb.stream")
sGo.Type = 1
sGo.Mode = 3
sGo.Open
posB = 1
posB = instrb(posB,binData,binCrlf)
posE = instrb(posB+1,binData,binCrlf)
'response.Write posB & " | " & posE & "<br>"
sCome.Position = posB+1
sCome.CopyTo sGo,posE-posB-2
sGo.Position = 0
sGo.Type = 2
sGo.Charset = "gb2312"
strData = sGo.ReadText
sGo.Close
'response.Write strData & "<hr>"
posSB = 1
posSB = instr(posSB,strData,"filename=""") + len("filename=""")
posSE = instr(posSB,strData,"""")
if posSE > posSB then
strPath = mid(strData,posSB,posSE-posSB)
'response.Write "本地路径：" & strPath & "<br>"
'response.Write "文件名：" & getFileNamefromPath(strPath) & "<br>"
posB = posE
posE = instrb(posB+1,binData,binCrlf)
'response.Write posB & " | " & posE & "<br>"
sGo.Type = 1
sGo.Mode = 3
sGo.Open
sCome.Position = posB
sCome.CopyTo sGo,posE-posB-1
sGo.Position = 0
sGo.Type = 2
sGo.Charset = "gb2312"
strData = sGo.ReadText
sGo.Close
strContentType = mid(strData,16) '此处因为固定的，所以省略查找 :-)
'response.Write "图片类型：" & strContentType & "<hr>"
posB = posE+2
posE = instrb(posB+1,binData,binCrlf)
'response.Write posB & " | " & posE & "<br>"
sGo.Type = 1
sGo.Mode = 3
sGo.Open
sCome.Position = posB+1
sCome.CopyTo sGo,posE-posB-2
sGo.Position = 0
strData = sGo.Read
sGo.Close
'response.Write lenb(strData) & "<br>"
dim cn, rs, sql
set cn = server.CreateObject("adodb.connection")
cn.Open cnstr
set rs = server.CreateObject("adodb.recordset")
sql = "select * from tblImage"
rs.Open sql,cn,1,3
rs.AddNew
rs.Fields("content-type").Value = strContentType
rs.Fields("image").AppendChunk strData
rs.Update
rs.Close
set rs = nothing
cn.Close
set cn = nothing
response.Write "图片保存成功！" & "<br>"
else
response.Write "没有上传图片！" & "<br>"
end if
set sGo = nothing
sCome.Close
set sCome = nothing
else
%>
<form id="frmUpload" name="frmUpload" action="SimpleImageToData.asp" method="post" target="_self" enctype="multipart/form-data">
<INPUT id="filImage" type="file" name="filImage" size="40">
<BR>
<INPUT id="btnUpload" type="submit" value="Upload" name="btnUpload">
</form>
<%
end if
%>
</body>
</HTML>
３、ShowImageListFromData.asp
<%@ Language=VBScript %>
<% option explicit %>
<html>
<head>
<title>显示数据库中已有图片的列表</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
</head>
<body>
<p><a href="SimpleImageToData.asp">上传图片</a>
<a href="ShowImageListFromData.asp">显示图片</a><hr></p>
<table border=0 cellpadding=2 cellspacing=2>
<tr>
<td valign=top>
<%
dim cnstr
cnstr = "driver={Microsoft Access Driver (*.mdb)};dbq=" & server.MapPath("./upload.mdb")
dim cn, sql, rs
set cn = server.CreateObject("adodb.connection")
cn.Open cnstr
sql = "select sn,[content-type],image from tblImage"
set rs = cn.Execute(sql)
response.Write "<table border=1 cellspacing=2 cellpadding=5>"
response.Write "<tr>"
response.Write "<th>序列号</th><th>图片类型</th><th>图片</th>"
response.Write "</tr>"
do until rs.eof
response.Write "<tr>"
response.Write "<td>" & rs("sn") & "</td>"
response.Write "<td>" & rs("content-type") & "</td>"
response.Write "<td><a href='ShowImageListFromData.asp?sn=" & rs("sn") & "'>看图</a></td>"
response.Write "</tr>"
rs.movenext
loop
response.Write "</table>"
cn.Close
set cn = nothing
%>
</td>
<td valign=top>
<%
dim sn
sn = request.QueryString("sn")
if sn = "" then
response.Write "没有指定图片！"
else
response.Write "<img border=1 src=ShowImageFromData.asp?sn=" & sn & ">"
end if
%>
</td>
</tr>
</table>
</body>
</html>
４、ShowImageFromData.asp
<%@ Language=VBScript %>
<% option explicit %>
<%
dim sn
sn = request.QueryString("sn")
if sn = "" then response.End
dim cnstr
cnstr = "driver={Microsoft Access Driver (*.mdb)};dbq=" & server.MapPath("./upload.mdb")
dim cn, sql, rs
set cn = server.CreateObject("adodb.connection")
cn.Open cnstr
sql = "select sn,[content-type],image from tblImage where sn=" & cint(sn)
set rs = cn.Execute(sql)
response.ContentType = rs("content-type")
response.BinaryWrite rs("image")
set rs = nothing
cn.Close
set cn = nothing
%>
上面讲了单个图片文件保存到数据库，下面讲一下文本信息与图片文件同时提交保存到数据库，图片文件也可保存到磁盘文件。
MultiInputOrImageToData.asp
<%@ Language=VBScript %>
<% option explicit %>
<%
'把一段二进制数据写入到一个文件
sub saveBin2File(srmSource,posB,posLen,strPath)
dim srmObj
set srmObj = server.CreateObject("adodb.stream")
srmObj.Type = 1
srmObj.Mode = 3
srmObj.Open
srmSource.Position = posB-1
srmSource.CopyTo srmObj,posLen
srmObj.Position = 0
srmObj.SaveToFile strPath,2 '如果该文件已经存在，无条件覆盖
srmObj.Close
set srmObj = nothing
end sub
'二进制数据转换为字符串，包括汉字
function getTextfromBin(srmSource,posBegin,posLen)
dim srmObj, strData
set srmObj = server.CreateObject("adodb.stream")
srmObj.Type = 1
srmObj.Mode = 3
srmObj.Open
srmSource.position = posBegin-1 '位置计数首数不一样，这个对象是对0开始的
srmSource.CopyTo srmObj,posLen
srmObj.Position = 0
srmObj.Type = 2
srmObj.Charset = "gb2312"
strData = srmObj.ReadText
srmObj.Close
set srmObj = nothing
getTextfromBin = strData
end function
'双字节字符串转换成单字节字符串
function getSBfromDB(bytString)
dim bin, i
bin = ""
for i=1 to len(bytString)
bin = bin & chrb(asc(mid(bytString,i,1)))
next
getSBfromDB = bin
end function
'单字节字符串转换成双字节字符串
function getDBfromSB(bitString)
dim str, i
str = ""
for i=1 to lenb(bitString)
str = str & chr(ascb(midb(bitString,i,1)))
next
getDBfromSB = str
end function
'从一个完整路径中析出文件名称
function getFileNamefromPath(strPath)
getFileNamefromPath = mid(strPath,instrrev(strPath,"\")+1)
end function
'判断函数
function iif(cond,expr1,expr2)
if cond then
iif = expr1
else
iif = expr2
end if
end function
'定义数据库连接字符串
dim cnstr
cnstr = "driver={Microsoft Access Driver (*.mdb)};dbq=" & server.MapPath("./upload.mdb")
%>
<HTML>
<HEAD>
<title>多个表单域或图像同步保存到数据库</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
</HEAD>
<body>
<p>导航菜单：<b>上传图片</b> <a href="ShowImageListFromData2.asp">显示图片</a><hr></p>
<%
if request.ServerVariables("REQUEST_METHOD") = "POST" then
dim sCome, binData
dim posB, posE, posSB, posSE
dim binCrlf, binSub
dim strTitle, strFileName, strContentType, posFileBegin, posFileLen, aryFileInfo
dim i, j
dim dicData
dim strName,strValue
binCrlf = getSBfromDB(vbcrlf) '定义一个单字节的回车换行符
binSub = getSBfromDB("--") '定义一个单字节的“--”字符串
set sCome = server.CreateObject("adodb.stream")
sCome.Type = 1 '指定返回数据类型 adTypeBinary=1,adTypeText=2
sCome.Mode = 3 '指定打开模式 adModeRead=1,adModeWrite=2,adModeReadWrite=3
sCome.Open
sCome.Write request.BinaryRead(request.TotalBytes)
sCome.Position = 0
binData = sCome.Read
'response.BinaryWrite binData '调试用：显示提交的所有数据
'response.Write "<hr>" '调试用
posB = instrb(binData,binSub)
posB = instrb(posB,binData,bincrlf) + 2 '+2是加入回车换行符本身的长度
posB = instrb(posB,binData,getSBfromDB("name=""")) + 6
set dicData = server.CreateObject("scripting.dictionary") '用来保存信息
do until posB=6
posE = instrb(posB,binData,getSBfromDB(""""))
'Response.Write "name=" & getTextfromBin(sCome,posB,posE-posB) & "<br>"
strName = getTextfromBin(sCome,posB,posE-posB)
posB = posE + 1 '指针移动到“"”的后面
posE = instrb(posB,binData,bincrlf)
'Response.Write posB & "->" & posE & "<br>"
if instrb(midb(binData,posB,posE-posB),getSBfromDB("filename=""")) > 0 then '判断成功表示这是一个file域
posB = instrb(posB,binData,getSBfromDB("filename=""")) + 10
posE = instrb(posB,binData,getSBfromDB(""""))
if posE>posB then
'response.Write "filename=" & getTextfromBin(sCome,posB,posE-posB) & "<br>"
strFileName = getFileNamefromPath(getTextfromBin(sCome,posB,posE-posB))
posB = instrb(posB,binData,getSBfromDb("Content-Type:")) + 14
posE = instrb(posB,binData,bincrlf)
'response.Write "content-type=" & getTextfromBin(sCome,posB,posE-posB) & "<br>"
strContentType = getTextfromBin(sCome,posB,posE-posB)
posB = posE + 4 '这个地方换了两行，具体参看输出的原始二进制数据
posE = instrb(posB,binData,binSub)
'response.Write "image data="
'saveBin2File sCome,posB,posE-posB-1,server.MapPath("./") & "\test.jpg"
'Response.Write "<img src='test.jpg' border=0><br>"
posFileBegin = posB
posFileLen = posE-posB-1
strValue = strFileName & "," & strContentType & "," & posFileBegin & "," & posFileLen
else
'Response.Write "没有上传文件！" & "<br>"
strValue = ""
end if
else
posB = posE + 4 '这个地方换了两行，具体参看输出的原始二进制数据
posE = instrb(posB,binData,binCrlf)
'Response.Write "value=" & getTextfromBin(sCome,posB,posE-posB) & "<br>" '这个后面没有“"”，所以不用-1
strValue = getTextfromBin(sCome,posB,posE-posB)
end if
dicData.Add strName,strValue
posB = posE + 2
posB = instrb(posB,binData,bincrlf) + 2
posB = instrb(posB,binData,getSBfromDB("name=""")) + 6
loop
strTitle = dicData.Item("txtTitle")
aryFileInfo = dicData.Item("filImage")
if aryFileInfo <> "" then '有文件数据上传
aryFileInfo = split(aryFileInfo,",")
strFileName = aryFileInfo(0)
strContentType = aryFileInfo(1)
posFileBegin = aryFileInfo(2)
posFileLen = aryFileInfo(3)
sCome.Position = posFileBegin-1
binData = sCome.Read(posFileLen)
dim cn, rs, sql
set cn = server.CreateObject("adodb.connection")
cn.Open cnstr
set rs = server.CreateObject("adodb.recordset")
sql = "select title,[content-type],image from tblImage2"
rs.Open sql,cn,1,3
rs.AddNew
rs.Fields("title").Value = strTitle
rs.Fields("content-type").Value = strContentType
'数据保存到数据库
rs.Fields("image").AppendChunk binData
'如果数据以文件形式保存到磁盘上，用下面这句
'saveBin2File sCome,posFileBegin,posFileLen,server.MapPath("./") & strFileName
rs.Update
rs.Close
set rs = nothing
cn.Close
set cn = nothing
Response.Write "<p>文件保存成功！</p>"
else
Response.Write "<p>没有上传文件！</p>"
end if
sCome.Close
set sCome = nothing
else
%>
<form id="frmUpload" name="frmUpload" action="<%=Request.ServerVariables("script_name")%>" method="post" target="_self" enctype="multipart/form-data">
<p>标题：<input id="txtTitle" type="text" name="txtTitle" size="40"></p>
<p>图片：<INPUT id="filImage" type="file" name="filImage" size="40"></p>
<INPUT id="btnUpload" type="submit" value="Upload" name="btnUpload">
</form>
<%
end if
%>
</body>
</HTML>
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