mySql Common Commands

CREATE TABLE foo LIKE bar;

CREATE TABLE IF NOT EXISTS offices_bk

SELECT * FROM

    offices;

==

CREATE TABLE IF NOT EXISTS new_table LIKE existing_table;

INSERT new_table

SELECT * FROM existing_table;

ALTER TABLE <tablename> CHANGE COLUMN <colname> <colname> VARCHAR(65536);

ALTER TABLE emp MODIFY COLUMN name VARCHAR(100);

Or use CHANGE, but that means you have to give the column name twice (because CHANGE allows you to change the name of the column too).
ALTER TABLE emp CHANGE COLUMN name name VARCHAR(100);