如何解決在執(zhí)行數(shù)據(jù)庫查詢中的特殊字符的問題    


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 【batman】 于 99-8-22 下午 10:54:14 加貼在 Joy ASP ↑：

如何解決在執(zhí)行數(shù)據(jù)庫查詢中的特殊字符的問題
在進(jìn)行數(shù)據(jù)庫的查詢時，會經(jīng)常遇到這樣的情況：
例如想在一個用戶數(shù)據(jù)庫中查詢他的用戶名和他的密碼，
但恰好該用戶使用的名字和密碼中有特殊的字符，例如單引號，“|”號
雙引號或者連字符“&”
例如他的名字是1'test，密碼是A|&900
這時當(dāng)你執(zhí)行以下的查詢語句時，肯定會抱錯：
SQL = "SELECT * FROM SecurityLevel WHERE UID='" & UserID & "'"
   SQL = SQL & " AND PWD='" & Password & "'" 
因?yàn)槟愕腟QL將會是這樣：
  SELECT * FROM SecurityLevel WHERE UID='1'test'
   AND PWD='A|&900' 
在SQL中，"|"為分割字段用的，顯然會出錯了。現(xiàn)在提供下面的幾個函數(shù)
專門用來處理這些頭疼的東西：

   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 

有了上面幾個函數(shù)后，當(dāng)你在執(zhí)行一個sql前，請先使用
SQL = "SELECT * FROM SecurityLevel WHERE UID='" & SQLFixup(UserID) & "'"
   SQL = SQL & " AND PWD='" & SQLFixup(Password) & "'" 





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