How can I get the target table in PostgreSQL?

The table look like this

number      day amount
013xxxxxxxx 1   62773
013xxxxxxxx 8   52963
013xxxxxxxx 9   10810
013xxxxxxxx 10  84193
013xxxxxxxx 11  91791
019xxxxxxxx 1   89055
019xxxxxxxx 3   85366
019xxxxxxxx 5   47318

• In the above table. It is source table. Here we can see all the day number is not available. So I need to add those unavailable rows with amount 0.

I want the table like this.

number      day amount
013xxxxxxxx 1   62773
013xxxxxxxx 2   0
013xxxxxxxx 3   0
013xxxxxxxx 4   0
013xxxxxxxx 5   0
013xxxxxxxx 6   0
013xxxxxxxx 7   0
013xxxxxxxx 8   52963
013xxxxxxxx 9   10810
013xxxxxxxx 10  84193
013xxxxxxxx 11  91791
019xxxxxxxx 1   89055
019xxxxxxxx 2   0
019xxxxxxxx 3   85366
019xxxxxxxx 4   0
019xxxxxxxx 5   47318

>Solution :

You can write this query (Result here)

with x as (SELECT distinct test.number,generated_day FROM generate_series(1, 31) as generated_day, test),
y as (SELECT distinct test.number, MAX(day) OVER (PARTITION BY number) AS max_day FROM test)
select x.number,x.generated_day,coalesce(t.amount,0)
from x left join test t on t."number" = x.number and t.day = x.generated_day
where x.generated_day <= (SELECT MAX(day) max_day FROM test where test.number = x.number) 
order by 1, 2