MySQL - How to Change VARCHAR Field Length
Values in VARCHAR columns are variable-length strings. The length can be specified as a value from 0 to 255 before MySQL 5.0.3, and 0 to 65,535 in 5.0.3 and later versions. The effective maximum length of a VARCHAR in MySQL 5.0.3 and later is subject to the maximum row size (65,535 bytes, which is shared among all columns) and the character set used.
So, we could easily change field's length to be longer than 255 characters if (and only if!) MySQL we work with is version 5.0.3+:
1) Login to phpMyAdmin and go to a database