combine two columns show range in third column (concat?)

Example of what I have

col1 col2 col3
246 247
257 283
01 04

what I would like to do


col1 col2 col3
246 247 246,247
257 260 257,258,259,260
01 04 01,02,03,04


what I have tried

SELECT master,start,end,
end-start as number,
concat(start+1,',') as numbercombine
FROM build LIMIT 20;




SELECT master,start,end,
if( between start and end,floor(1 + rand() * end)) as number
FROM buildLIMIT 20;

 

I found a way to do it with (php mysql) but not with just mysql