Custom anti-SQL injection functions

/ ************************************************ *sql Anti-injection function * @time June 24, 2014 18:50:59 **/     Public functionSafe_replace ($string){        $string=Str_replace('%20 ', ',$string); $string=Str_replace('%27 ', ',$string); $string=Str_replace('%2527 ', ',$string); $string=Str_replace(‘*‘,‘‘,$string); $string=Str_replace(' ' ', ' &quot; ',$string); $string=Str_replace("‘",‘‘,$string); $string=Str_replace(‘"‘,‘‘,$string); $string=Str_replace(‘;‘,‘‘,$string); $string=Str_replace(' < ', ' &lt; ',$string); $string=Str_replace(' > ', ' &gt; ',$string); $string=Str_replace("{",‘‘,$string); $string=Str_replace(‘}‘,‘‘,$string); $string=Str_replace("or", "",$string); $string=Str_replace("=","",$string); $string=Str_replace("and", "",$string); $string=Str_replace("Execute", "",$string); $string=Str_replace("Update", "",$string); $string=Str_replace("Count", "",$string); $string=Str_replace("Chr", "",$string); $string=Str_replace("Mid", "",$string); $string=Str_replace("Master", "",$string); $string=Str_replace("Truncate", "",$string); $string=Str_replace("Char", "",$string); $string=Str_replace("Declare", "",$string); $string=Str_replace("Select", "",$string); $string=Str_replace("Create", "",$string); $string=Str_replace("delete", "",$string); $string=Str_replace("Insert", "",$string); return $string; }