数据库查询中的特殊字符的问题
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1"test,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="1"test" 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数据库 转义字符:
复制代码 代码如下:
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) """