How To Fill Missing Dates In Bigquery?

This question is related to How to fill missing dates and values in partitioned data?, but since the solution doesn't work for BigQuery, I'm posting the question again. I have the

Solution 1:

this should work

with base as (

select 'A' as name,           '01/01/2020' as date,     1.5 as val  union all
select 'A' as name,           '01/03/2020' as date,     2 as val union all
select 'A' as name,           '01/06/2020' as date,     5 as val union all
select 'B' as name,           '01/02/2020' as date,     90 as val union all
select 'B' as name,           '01/07/2020' as date,     10 as val
),

missing_dates as (

select name,dates as date from 
UNNEST(GENERATE_DATE_ARRAY('2019-12-29', '2020-01-09', INTERVAL 1 DAY)) AS dates cross join (select distinct name from base)

), joined as (
select distinct missing_dates.name, missing_dates.date,val 
from  missing_dates 
left join base on missing_dates.name = base.name 
and  parse_date('%m/%d/%Y', base.date) = missing_dates.date

)

select * except(val), 
ifnull(first_value(val ignore nulls) over(partition by name order by date ROWS BETWEEN CURRENT ROW AND
    UNBOUNDED FOLLOWING),1) as va1 
from joined