| 发表于：2008-01-18 16:08:171楼 得分:0 |
'读写二进制数据（流)
'函数名:adostream
'参数: p_cnn adodb连接,tabname 目标数据表,fldname 目标字段,wherestr 更新条件,
' filename 源文件名或由流生成的文件名,rsstyle 记录集的操作类型.w:file to recode,r:recode to file
'返回值:
'例: call adostream（p_cnn,"achgoods","gdsphoto","where gdsid='001'","c:\tmp.bmp","w")
public function adostream（p_cnn as adodb.connection, _
tabname as string, _
fldname as string, _
optional wherestr as string = "", _
optional filename as string, _
optional rsstyle as smrstype = rswrite) as string
dim strsql as string
dim tmpfilename as string
dim rs as new adodb.recordset
dim adosem as new adodb.stream
dim returnval as string
dim workpath as string
dim rstype as long
dim rsstylestr as string
err.clear
on error resume next
workpath = app.path
if p_cnn.state <> 1 then p_cnn.open
if right$（workpath, 1) <> "\" then workpath = workpath & "\"
returnval = ""
adosem.type = adtypebinary '流数据类型
adosem.open '打开流
'/-----------------------------------------------------------
'将流写入记录集
rstype = rsstyle
rsstylestr = choose（rstype, "w", "r")
if rsstylestr = "w" then
if left$（trim$（ucase$（wherestr)), len（"where")) <> ucase$（"where") then wherestr = " where " & trim$（wherestr)
strsql = "select top 1 [" & tabname & "].[" & fldname & "] from [" & tabname & "] " & wherestr
set rs = rsopen（p_cnn, strsql, false) '连接式记录集
if not （rs.eof and rs.bof) then
rs.movefirst
adosem.loadfromfile filename '将文件load到流
doevents
rs.fields（fldname).appendchunk adosem.read
rs.update
end if
adostream = ""
elseif rsstyle = "r" then
'/将流从记录集中取出
if len（trim$（filename)) = 0 then filename = "tmpfile.bmp"
if len（trim$（dir$（tmpfilename, vbnormal + vbhidden))) > 0 then kill filename
if left$（trim$（ucase$（wherestr)), len（"where")) <> ucase$（"where") then wherestr = " where " & trim$（wherestr)
strsql = "select top 1 [" & tabname & "].[" & fldname & "] from [" & tabname & "] " & wherestr
set rs = rsopen（p_cnn, strsql)
if not （rs.eof and rs.bof) then
rs.movefirst
if not （isnull（rs.fields（fldname))) then
tmpfilename = workpath & filename
adosem.write rs.fields（fldname).getchunk（rs.fields（fldname).actualsize)
doevents
adosem.savetofile tmpfilename, iif（len（trim$（dir$（tmpfilename, vbnormal + vbhidden))) > 0, adsavecreateoverwrite, adsavecreatenotexist)
adostream = tmpfilename
else
adostream = ""
end if
else
adostream = ""
end if
end if
if adosem.state = adstateopen then
adosem.close
set adosem = nothing
end if
if rs.state = adstateopen then
rs.close
set rs = nothing
end if
err.clear
end function | | |
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