How to update a column of char type in mysql to increase its length

Question

How to increase the length of a column with char data type in mysql ?

The following query

ALTER TABLE tablename ALTER COLUMN columnname varchar(30) not null;

is not working.

Point out my error please. Thanks

Answer 1

ALTER TABLE `tablename` CHANGE `columnname` `columnname` VARCHAR( 30 ) NOT NULL 

OR

ALTER TABLE `tablename` MODIFY `columnname` VARCHAR( 30 ) NOT NULL 

Answer 2

please try query given below

ALTER TABLE tablename  MODIFY  columnname varchar(30) NOT NULL;  

You can refer to this tutorial