[MySQL][SQL] Change column collation to utf8

SQL statment :

ALTER TABLE '<tablename>' CHANGE '<column_name>' '<column_name>' VARCHAR( 50 ) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL
 

Use my case to be an example:

ALTER TABLE  'plants' CHANGE  'p121'  'p121' VARCHAR( 50 ) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL

Result: