SQL注入过滤

SQL注入#region SQL注入
        public static void SQLZ()
        {
                 HttpContext.Current.Request.QueryString;
                 CheckSQLZ(HttpContext.Current.Request.QueryString);
        }

        private static void CheckSQLZ(System.Collections.Specialized.NameValueCollection qs)
        {
            if (qs.Count > 0)
            {
                for (int i = 0; i < qs.Count; i++)
                {
                    if (!Z(qs[i].ToLower()))
                    {
                        HttpContext.Current.Response.Clear();
                        HttpContext.Current.Response.Write("您好，SQL注入？");
                        HttpContext.Current.Response.End();
                    }
                }
            }
        }
        
        private static string[] al = ";|and|1=1|exec|insert|select|delete|update|like|count|chr|mid|master|or|truncate|char|declare|join".Split('|');
        public static bool Z(string v)
        {
            if (v.Trim() != "")
            {
                foreach (string a in al)
                {
                    if (v.IndexOf(a + " ") > -1 || v.IndexOf(" " + a) > -1)
                    {
                        return false;
                    }
                }
            }
            return true;
        }
        #endregion