PHP: Prevent SQL Injection Attacks

SQL injection is a typical code injection attack that exploits weaknesses of application in the database layer. SQL injection vulnerability is created when one scripting or programming language is embedded in or used as input in another with failure to verify the legality or filter for potential dangerous codes.

SQL injections are possible when input from user is either incorrectly filtered for string literals embedded in SQL query statements or it’s not strongly typed thereby incurring unexpected execution.

The solution to this is to never trust user input data by default, especially those that will be used in a SQL statement. Check for data type and escape string literals before committing them into a query.

7 thoughts on “PHP: Prevent SQL Injection Attacks”

  1. Pingback: PHP: Escape String for SQL, mysqli::real_escape_string and PDO | Make A Website

  2. Pingback: A few database security tips – things to do to effectively protect MySQL databases

  3. function makeEncode($sql)
    $sql = preg_replace(sql_regcase(“/(from|select|insert|delete|where|drop table|like|show tables|\’|’\| |=|-|;|,|\|’||#|\*|–|\\\\)/”), “” ,$sql);
    $sql = trim($sql);
    $sql = strip_tags($sql);
    $sql = (get_magic_quotes_gpc()) ? stripslashes($sql) : mysql_real_escape_string($sql);
    $sql = htmlentities($sql);
    return $sql;

  4. Write a function like that
    function makeEncode($value)
    $value = trim(htmlentities($value));
    $value = stripslashes($value);
    $value = mysqli_real_escape_string($this->dbLink,$value);
    return $value;
    then use this when entering data into mysql database

Comments are closed.

Scroll to Top