mysql_real_escape_string

CI中：

$this->db->select('*')->where("username","skcdian")->where("password","' OR ''='")->get("user")->result(); 

SELECT * FROM (user) WHERE username = 'skcdian' AND password = '\' OR \'\'=\''

$password="'' OR ''='' ";mysql_real_escape_string($password);

\'\' OR \'\'=\'\'

$password="'' OR ''='' ";$data1=$this->db->query("SELECT * FROM (user) WHERE username = 'skcdian' AND password = {$password};")->result();

CI\system\database\drivers\mysql\mysql_driver.php

function escape_str($str, $like = FALSE){	if (is_array($str))	{		foreach ($str as $key => $val)   		{			$str[$key] = $this->escape_str($val, $like);   		}   		return $str;   	}	if (function_exists('mysql_real_escape_string') AND is_resource($this->conn_id))	{		$str = mysql_real_escape_string($str, $this->conn_id);	}	elseif (function_exists('mysql_escape_string'))	{		$str = mysql_escape_string($str);	}	else	{		$str = addslashes($str);	}	// escape LIKE condition wildcards	if ($like === TRUE)	{		$str = str_replace(array('%', '_'), array('\\%', '\\_'), $str);	}	return $str;}