ASP技术-数据库查询中的特殊字符的问题

2018-09-06 11:24

阅读:485

  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A900
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=A900
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)


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