ASP执行数据库查询中的特殊字符的处理

导读：本文介绍了查询数据时，特殊字符的处理办法。

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：

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) & "'"