Order by numbers followed by alphabet and then null values I have below column in my database:

abc
1
2
null
100
6


I want to sort and show these values as per below sequence:

1
2
6
100
abc
null


Anyone please help me to solve it.
Consider below query:

select * from test_table where status=1 order by test_column DESC


OR

 select * from test_table where status=1 order by if((test_column = '' OR test_column IS NULL),'999999',test_column) DESC
select
*
from
t
order by
case 
when col regexp '^[0-9]' then 1
when col regexp '^[a-zA-Z]' then 2
when col = '' or col is null then 3
end
, col * 1 /*this converts to number, so that 100 is not sorted before 2*/
, col /*finally sort strings correctly*/