通用 文件保存至数据库,从数据库写入磁盘 程序代码

通用 文件保存至数据库,从数据库写入磁盘 程序代码 ----20040809
这几天我休假中，正好有时间继续编写mycodelibrary 1.5版,今天晚上刚好写到文件与数据库存入取出模块，在论坛上此问题见的也较多，所以特此公开此部分代码，供有需者参考使用.代码虽然可以完整的正常使用，但还是需要做些错误方面的处理。

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@#整理时间：2004-8-9 3:32:48
option explicit
public objconn as new adodb.connection
public m_connstring as string
private function exists(byval str_filename as string, _
byval int_val as vbfileattribute) as boolean
@#--------------------------------------------------------------------------------
@# project : mycodelibrary 1.5
@# procedure : exists
@# description: [判断文件或目录是否存在]
@# created by : ronggang （zhouronggang@163.com）
@# date-time : 2004-8-9-2:31:45
@#
@# parameters : str_filename (string)
@# int_val (vbfileattribute)
@#--------------------------------------------------------------------------------
on error resume next
if len(str_filename) = 0 then
exists = false
exit function
end if
if int_val <> vbdirectory then @#如果不是目录
@#如果为空表示文件不存在
if dir(str_filename) = "" then
exists = false
else
exists = true
end if
else
if dir(str_filename, vbdirectory) = "" then
exists = false
else
exists = true
end if
end if
end function
public sub binvalue(byval strfilename as string, byref objfield as field)
@#--------------------------------------------------------------------------------
@# project : mycodelibrary 1.5
@# procedure : binvalue
@# description: [将文件保存至数据库中]
@# created by : wangfeng
@# date-time : 2004-8-9-2:20:37
@#
@# parameters : strfilename (string)
@# objfield (field)
@#--------------------------------------------------------------------------------
@#此方法需要做错误处理，以防文件己打开
dim objstream as stream
if not exists(strfilename, vbnormal) then @#如果文件不存则抛出异常
err.raise 50001, "dbfile", "文件不存在!"
exit sub
end if
set objstream = new adodb.stream
with objstream
.type = adtypebinary
.open
.loadfromfile strfilename
objfield.value = .read
end with
set objstream = nothing
end sub
public function binvalue2file(byval strfilename as string, byref objfield as field, optional overwrite as boolean = false) as boolean
@#--------------------------------------------------------------------------------
@# project : mycodelibrary 1.5
@# procedure : binvalue2file
@# description: [将数据库中的二进制数据保存为文件]
@# created by : wangfeng
@# date-time : 2004-8-9-2:22:33
@#
@# parameters : strfilename (string) 目标文件
@# objfield (field) 数据字段名
@# overwrite (boolean = false) 是否覆盖现有存在的文件
@# true 覆盖 false(默认)不存在时保存
@#--------------------------------------------------------------------------------
on error goto errorhander
dim objstream as stream
dim returnmsg as vbmsgboxresult
set objstream = new adodb.stream
with objstream
.type = adtypebinary
.open
.write objfield.value
if overwrite then
.savetofile strfilename, adsavecreateoverwrite
else
.savetofile strfilename, adsavecreatenotexist
end if
end with
binvalue2file = true @#保存成功返回true
101:
set objstream = nothing
exit function
errorhander:
binvalue2file = false
goto 101
end function
public function getfilename(byval strpathfilename) as string
dim ipos as long
ipos = vba.instrrev(strpathfilename, "\")
getfilename = mid(strpathfilename, ipos + 1)
end function
public function getpathname(optional strpathname as string) as string
@#sfilename = mid(getpathname, ipos + 1)
dim ipos as long
ipos = vba.instrrev(strpathname, "\")
getpathname = mid(strpathname, 1, ipos)
end function

原文转自：http://www.ltesting.net