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(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數(shù)據(jù)庫 轉(zhuǎn)義字符：
復(fù)制代碼 代碼如下:
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) """
