在進(jìn)行數(shù)據(jù)庫的查詢時(shí)，會(huì)經(jīng)常遇到這樣的情況：
　　例如想在一個(gè)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(hào)，“|”號(hào)，雙引號(hào)或者連字符“&”。
　　例如他的名字是1"test，密碼是A|&900
　　這時(shí)當(dāng)你執(zhí)行以下的查詢語句時(shí)，肯定會(huì)報(bào)錯(cuò)：
SQL = "SELECT * FROM SecurityLevel WHERE UID="" & UserID & """
SQL = SQL & " AND PWD="" & Password & """
　　因?yàn)槟愕腟QL將會(huì)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(huì)出錯(cuò)了。現(xiàn)在提供下面的幾個(gè)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(gè)函數(shù)后，當(dāng)你在執(zhí)行一個(gè)sql前，請(qǐng)先使用
SQL = "SELECT * FROM SecurityLevel WHERE UID="" & SQLFixup(UserID) & """
SQL = SQL & " AND PWD="" & SQLFixup(Password) & """