在进行数据库的查询时,会经常遇到这样的情况:
例如想在一个用户数据库中查询他的用户名和他的密码,但恰好该用户使用的名字和密码中有特殊的字符,例如单引号,“|”号,双引号或者连字符“&”。
例如他的名字是1test,密码是a|&900,这时当你执行以下的查询语句时,肯定会报错:
sql = “select * from securitylevel where uid=” & userid & “”
sql = sql & ” and pwd=” & password & “”
因为你的sql将会是这样:
select * from securitylevel where uid=1test and pwd=a|&900
在sql中,”|”为分割字段用的,显然会出错了。现在提供下面的几个函数,专门用来处理这些头疼的东西:
function replacestr (textin, byval searchstr as string, _
byval replacement as string, _
byval compmode as integer)
dim worktext as string, pointer as integer
if isnull(textin) then
replacestr = null
else
worktext = textin
pointer = instr(1, worktext, searchstr, compmode)
do while pointer > 0
worktext = left(worktext, pointer – 1) & replacement & _
mid(worktext, pointer + len(searchstr))
pointer = instr(pointer + len(replacement), worktext, _
searchstr, compmode)
loop
replacestr = worktext
end if
end function
function sqlfixup(textin)
sqlfixup = replacestr(textin, “”, “”, 0)
end function
function jetsqlfixup(textin)
dim temp
temp = replacestr(textin, “”, “”, 0)
jetsqlfixup = replacestr(temp, “|”, ” & chr(124) & “, 0)
end function
function findfirstfixup(textin)
dim temp
temp = replacestr(textin, “”, ” & chr(39) & “, 0)
findfirstfixup = replacestr(temp, “|”, ” & chr(124) & “, 0)
end function
有了上面几个函数后,当你在执行一个sql前,请先使用:
sql = “select * from securitylevel where uid=” & sqlfixup(userid) & “”
sql = sql & ” and pwd=” & sqlfixup(password) & “”
