SQL convert rows to one Column

I have a table,

Output before pivoting:

keli |  onoma
-----+---------------
name |  Step1
a1   |  DSP
a2   |  Tekmiriosi

Expected output:

Step1 | DSP | Tekmiriosi

How to do that for three or more rows but always with to one-row column?

Answer

You can use conditional aggregation:

select max(onoma) filter (where keli = 'name'),
       max(onoma) filter (where keli = 'a1'),
       max(onoma) filter (where keli = 'a2')
from t;

However, I might suggest that you if you want all values in a single row that you just use arrays:

select array_agg(keli)
from t;