The MySQL reference manual does not provide a clearcut example on how to do this.
I have an ENUM-type column of country names that I need to add more countries to. W
Here is another way...
It adds "others" to the enum definition of the column "rtipo" of the table "firmas".
set @new_enum = 'others';
set @table_name = 'firmas';
set @column_name = 'rtipo';
select column_type into @tmp from information_schema.columns
where table_name = @table_name and column_name=@column_name;
set @tmp = insert(@tmp, instr(@tmp,')'), 0, concat(',\'', @new_enum, '\'') );
set @tmp = concat('alter table ', @table_name, ' modify ', @column_name, ' ', @tmp);
prepare stmt from @tmp;
execute stmt;
deallocate prepare stmt;