sql - MySQL Single Row Returned From Temporary Table -

i running following queries against database:

create temporary table med_error_third_party_tmp select `med_error_category`.description category, `med_error_third_party_category`.error_count error_count     `med_error_category` inner join `med_error_third_party_category` on med_error_category.`id` = `med_error_third_party_category`.`category`     year = 2003 group `med_error_category`.id; 

the problem when create temporary table , select * on returns multiple rows, query above returns 1 row. seems return single row unless specify group by, returns percentage of 1.0 should group by.

select category,         error_count/sum(error_count) percentage   med_error_third_party_tmp; 

here server specs:
server version: 5.0.77
protocol version: 10
server: localhost via unix socket

does see problem causing problem?

standard sql requires specify group clause if column not wrapped in aggregate function (ie: min, max, count, sum, avg, etc), mysql supports "hidden columns in group by" -- why:

select category,         error_count/sum(error_count) percentage   med_error_third_party_tmp; 

...runs without error. problem functionality because there's no group by, sum sum of error_count column entire table. other column values arbitrary - can't relied upon.

this:

select category,         error_count/(select sum(error_count)                       med_error_third_party_tmp) percentage   med_error_third_party_tmp; 

...will give percentage on per row basis -- category values duplicated because there's no grouping.

this:

  select category,           sum(error_count)/x.total percentage     med_error_third_party_tmp     join (select sum(error_count) total             med_error_third_party_tmp) x  group category 

...will gives percentage per category of sum of categories error_count values vs sum of error_count values entire table.