Bigquery - 行到列

Question

Im trying to convert rows into column (kind of pivot)

Current table(generated from a CTE)

with cte as (select date(start_time) as date, type, count(*) as total 
from table
where start_time >='2020-09-09'
group by 1,2
order by 1)

My expected output:

I tried this query, but it didn't work

with cte as (select date(start_time) as date, type, count(*) as total 
from table
where start_time >='2020-09-09'
group by 1,2
order by 1),
c1 as(
select date,total as C1 from cte where type='c1') ,
c2 as(
select date, total as C2 from cte where type='c2'),
c3 as(
select date,total as C3 from cte where type='c3')
select cte.date,c1.C1,c2.C2,c3.C3  from cte join c1 on cte.date=c1.date join c2 on cte.date=c2.date
join c3 on cte.date=c3.date join ext on cte.date=ext.date

It worked, but every row got added 3 times.

Answer 1

Use conditional aggregation:

select 
    date(start_time) start_date, 
    countif(cat = 'c1') c1, 
    countif(cat = 'c2') c2, 
    countif(cat = 'c3') c3
from mytable
where start_time >='2020-09-09'
group by date(start_time)