在進行數據庫的查詢時，會經常遇到這樣的情況：
例如想在一個用戶數據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
這時當你執行以下的查詢語句時，肯定會報錯：
SQL = "SELECT * FROM SecurityLevel WHERE UID="" & UserID & """
SQL = SQL & " AND PWD="" & Password & """
因為你的SQL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。現在提供下面的幾個函數 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
有了上面幾個函數后，當你在執行一個sql前，請先使用
SQL = "SELECT * FROM SecurityLevel WHERE UID="" & SQLFixup(UserID) & """
SQL = SQL & " AND PWD="" & SQLFixup(Password) & """