Можно ли заменять в SQL запросе ' на "?

<?php
	
	// DATA VALIDATION
	
	function xss_clean($data){

		// Fix &entity\n;
		$data = str_replace(array('&amp;','&lt;','&gt;'), array('&amp;amp;','&amp;lt;','&amp;gt;'), $data);
		$data = preg_replace('/(&#*\w+)[\x00-\x20]+;/u', '$1;', $data);
		$data = preg_replace('/(&#x*[0-9A-F]+);*/iu', '$1;', $data);
		$data = html_entity_decode($data, ENT_COMPAT, 'UTF-8');

		// Remove any attribute starting with "on" or xmlns
		$data = preg_replace('#(<[^>]+?[\x00-\x20"\'])(?:on|xmlns)[^>]*+>#iu', '$1>', $data);

		// Remove javascript: and vbscript: protocols
		$data = preg_replace('#([a-z]*)[\x00-\x20]*=[\x00-\x20]*([`\'"]*)[\x00-\x20]*j[\x00-\x20]*a[\x00-\x20]*v[\x00-\x20]*a[\x00-\x20]*s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:#iu', '$1=$2nojavascript...', $data);
		$data = preg_replace('#([a-z]*)[\x00-\x20]*=([\'"]*)[\x00-\x20]*v[\x00-\x20]*b[\x00-\x20]*s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:#iu', '$1=$2novbscript...', $data);
		$data = preg_replace('#([a-z]*)[\x00-\x20]*=([\'"]*)[\x00-\x20]*-moz-binding[\x00-\x20]*:#u', '$1=$2nomozbinding...', $data);

		// Only works in IE: <span style="width: expression(alert('Ping!'));"></span>
		$data = preg_replace('#(<[^>]+?)style[\x00-\x20]*=[\x00-\x20]*[`\'"]*.*?expression[\x00-\x20]*\([^>]*+>#i', '$1>', $data);
		$data = preg_replace('#(<[^>]+?)style[\x00-\x20]*=[\x00-\x20]*[`\'"]*.*?behaviour[\x00-\x20]*\([^>]*+>#i', '$1>', $data);
		$data = preg_replace('#(<[^>]+?)style[\x00-\x20]*=[\x00-\x20]*[`\'"]*.*?s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:*[^>]*+>#iu', '$1>', $data);

		// Remove namespaced elements (we do not need them)
		$data = preg_replace('#</*\w+:\w[^>]*+>#i', '', $data);

		do{
			// Remove really unwanted tags
			$old_data = $data;
			$data = preg_replace('#</*(?:applet|b(?:ase|gsound|link)|embed|frame(?:set)?|i(?:frame|layer)|l(?:ayer|ink)|meta|object|s(?:cript|tyle)|title|xml)[^>]*+>#i', '', $data);
		}while ($old_data !== $data);

		// we are done...
		return $data;
	
	}
	
	function slinj($input_text){
		$input_text = str_replace("'", "\"", $input_text);
		$input_text = iconv("UTF-8//IGNORE","WINDOWS-1251//IGNORE", htmlspecialchars(iconv("WINDOWS-1251//IGNORE","UTF-8//IGNORE", $input_text)));
		$input_text = mysql_real_escape_string($input_text);
		return $input_text;
	}
	
	function xss($input_text){
		$input_text = iconv("UTF-8//IGNORE","WINDOWS-1251//IGNORE", htmlspecialchars(iconv("WINDOWS-1251//IGNORE","UTF-8//IGNORE", $input_text)));
		$input_text = iconv("UTF-8//IGNORE","WINDOWS-1251//IGNORE", xss_clean(iconv("WINDOWS-1251//IGNORE","UTF-8//IGNORE", $input_text)));
		//$input_text = xss_clean($input_text);
		return $input_text;
	}
	
?>