SQL Injection is the hacking technique which attempts to pass SQL commands (statements) through a web application for execution by the backend database. If user input is inserted without modification into an SQL query, then the application becomes vulnerable to SQL injection
Generally, We give the various options of choices to choose on websites in form of checkbox and stores various values of choices in a column of MySQL database as a comma seperated . For example we store user’s preferred hobby in user table’s hobbies(varchar(250)) field(column). Value stored in this field may be like 1,2,5,6,1 or may be ‘sports’,’gardening’,’cooking’,’reading’.
Sometimes we need to get the last day of the month on specific date in mysql becoz every month has different last day eg. FEB. may have 28 or 29, JAN has 31 and APR has 30.
DAY() in MySQL returns the day of the month for a specified date. The day returned will be within the range of 1 to 31. If the given date is ‘2013-03-13’, the function will return 13.