SqlServer特殊字符转换&查询

Codesnip, currently in used in my project: /// summary /// Encode theuser-input (with special character) into SQL query statement /// special character like : ',[,/,_,%...etc /// /summary /// param name="strValue" user-input /param /// par

  

Codesnip, currently in used in my project:

 

    ///

/// Encode theuser-input (with special character) into SQL query statement

/// special character like : ',[,/,_,%...etc

///

/// user-input

///if it is encode for like statement

///SQL query statement
publicstaticstring sqlEncode(string strValue, bool isLikeStatement)

    {

        string rtStr = strValue;

        if (isLikeStatement)

        {

            rtStr = strValue.Replace("[", "[[]"); //此句一定要在最前

            rtStr = rtStr.Replace("_", "[_]");

            rtStr = rtStr.Replace("%", "[%]");

            rtStr = rtStr.Replace(@"/", "////");

        }

        rtStr = rtStr.Replace("'", "''");

 

        return rtStr;

    }

 

 

 

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查询SqlServer特殊字符 原文：Here

 

 

我们都知道SQL查询过程中，单引号“'”是特殊字符，所以在查询的时候要转换成双单引号“''”。

但这只是特殊字符的一个，在实际项目中，发现对于like操作还有以下特殊字符：下划线“_”，百分号“%”，方括号“[]”以及尖号“^”。

其用途如下：

下划线：用于代替一个任意字符（相当于正则表达式中的 ? ）

百分号：用于代替任意数目的任意字符（相当于正则表达式中的 * ）

方括号：用于转义（事实上只有左方括号用于转义，右方括号使用最近优先原则匹配最近的左方括号）

尖号：用于排除一些字符进行匹配（这个与正则表达式中的一样）

 

以下是一些匹配的举例，需要说明的是，只有like操作才有这些特殊字符，=操作是没有的。

a_b...	a[_]b%
a%b...	a[%]b%
a[b...	a[[]b%
a]b...	a]b%
a[]b...	a[[]]b%
a[^]b...	a[[][^]]b%
a[^^]b...	a[[][^][^]]b%

 

 

对于like操作，需要进行以下替换（注意顺序也很重要）

[ -> [[]     (这个必须是第一个替换的!!)

% -> [%]    (这里%是指希望匹配的字符本身包括的%而不是专门用于匹配的通配符)

_ -> [_]

^ -> [^]

 

 

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引用：Here

SQL encode and decode Function

2007-07-05 14:31

Function SQL_encode(strContent)
If isnull(strContent) = False Then
   strContent = replace(strContent, """", """)
   strContent = replace(strContent, "'", "'")
   strContent = replace(strContent, "+", "+")
   strContent = replace(strContent, "*", "*")
   strContent = replace(strContent, "-", "-")
   strContent = replace(strContent, "=", "=")
   strContent = replace(strContent, "   strContent = replace(strContent, "%", "%")
   strContent = replace(strContent, "_", "_")
   SQL_encode = strContent
End If
End Function

Function SQL_decode(strContent)
If isnull(strContent) = False Then
   strContent = replace(strContent, """, """")
   strContent = replace(strContent, "'", "'")
   strContent = replace(strContent, "+", "+")
   strContent = replace(strContent, "*", "*")
   strContent = replace(strContent, "-", "-")
   strContent = replace(strContent, "=", "=")
   strContent = replace(strContent, "<", "<")
strContent = replace(strContent, ">", ">")
   strContent = replace(strContent, "%", "%")
   strContent = replace(strContent, "_", "_")
   SQL_Decode = strContent
End If
End Function

edition 2006

-------------------------------------------------------------------

'transform any SQL operators to their ascii equivalent
function SQL_encode(strContent)

if isnull(strContent) = false then

   'transform sql operators to ascii equivalents
   strContent = replace(strContent, "'", "|Q|")
   strContent = replace(strContent, """", "|QQ|")
   strContent = replace(strContent, "+", "|PLUS|")
   strContent = replace(strContent, "*", "|STAR|")
   strContent = replace(strContent, "-", "|MINUS|")
   strContent = replace(strContent, "=", "|EQUALS|")
   strContent = replace(strContent, "   strContent = replace(strContent, ">", "|RIGHT|")
   strContent = replace(strContent, "%", "|PERCENT|")
   strContent = replace(strContent, "_", "|UNDER|")
   strContent = replace(strContent, "/", "|BACKS|")
   strContent = replace(strContent, "/", "|FRONTS|")

   SQL_encode = strContent

end if

end function

'tranform ascii characters to their SQL equivalent
function SQL_decode(strContent)

if isnull(strContent) = false then

   'transform sql operators
   strContent = replace(strContent, "|Q|", "'")
   strContent = replace(strContent, "|QQ|", """")
   strContent = replace(strContent, "|PLUS|", "+")
   strContent = replace(strContent, "|STAR|", "*")
   strContent = replace(strContent, "|MINUS|", "-")
   strContent = replace(strContent, "|EQUALS|", "=")
   strContent = replace(strContent, "|LEFT|", "   strContent = replace(strContent, "|RIGHT|", ">")
   strContent = replace(strContent, "|PERCENT|", "%")
   strContent = replace(strContent, "|UNDER|", "_")
   strContent = replace(strContent, "|BACKS|", "/")
   strContent = replace(strContent, "|FRONTS|", "/")

   SQL_Decode = strContent

end if

end function