I'm trying to add an address book using a php template that incorporates an SQL database.

Everything went to plan until I tried to increase the amount of characters in one of the fields. Here's how I attacked it:
PhpMyAdmin > Structure > Change > edited VARCHAR from 50 to 150
There was no change when I either add new data or edit existing data, I'm still only allowed 50 characters. I also tried restricting the limit to 4 but was still allowed 50. PhpMyAdmin said the table had been altered successfully.

My knowledge of php and SQL is next door to zero so I have no idea if this is a simple thing I'm unaware of, or something with too many possible variables to be answered in a forum situation.