An SQL injection is one of the most dangerous security issues. SQL injections are dangerous because they are a door wide open to hackers to enter the user system through their Web interface and to do whatever they please - i.e. delete tables, modify databases. The principal behind SQL injection is pretty simple. When an application takes user data as an input, there is an opportunity for a malicious user to enter carefully crafted data that causes the input to be interpreted as part of a SQL query instead of data. Databases are attractive targets because they typically contain critical application information.