PostgreSQL transpose rows in to columns - sql

Question

i have one query
select department_id,SUM(quantity) as Quantity,sales_report.date as Date from sales_report where date = '2018-10-04' GROUP BY department_id , Date ORDER BY department_id ASC;
which gives me output like below:
id quantity date
1 204 2018-10-04
2 88 2018-10-04
3 135 2018-10-04
4 72 2018-10-04
5 391 2018-10-04
6 134 2018-10-04
7 386 2018-10-04
8 421 2018-10-04
9 292 2018-10-04
10 86 2018-10-04
11 83 2018-10-04
12 34 2018-10-04
13 3435 2018-10-04
but I need data like this:
id 1 2 3 4 5 6 7 8 9 10 11 12 13
2018-10-04 204 88 135 72 391 134 386 421 292 86 83 34 3435
Can anyone help me to achieve this..

Answer 1

you can try this:
select sales_report.date,
sum(case when id=1 then quantity else 0 end) as '1',
sum(case when id=2 then quantity else 0 end) as '2',
sum(case when id=3 then quantity else 0 end) as '3',
sum(case when id=4 then quantity else 0 end) as '4',
sum(case when id=5 then quantity else 0 end) as '5',
sum(case when id=6 then quantity else 0 end) as '6',
sum(case when id=7 then quantity else 0 end) as '7',
sum(case when id=8 then quantity else 0 end) as '8',
sum(case when id=9 then quantity else 0 end) as '9',
sum(case when id=10 then quantity else 0 end) as '10',
sum(case when id=11 then quantity else 0 end) as '11',
sum(case when id=12 then quantity else 0 end) as '12',
sum(case when id=13 then quantity else 0 end) as '13'
from sales_report where date = '2018-10-04' GROUP BY Date ORDER BY date ASC

Answer 2

you need case when, from your output data set you could do this pivoting
select date, max(case when id=1 then quantity end) as 1_one,
max(case when id=2 then quantity end) as 2_one,
max(case when id=3 then quantity end) as 3_one,
max(case when id=4 then quantity end) as 4_one,
max(case when id=5 then quantity end) as 5_one,
max(case when id=6 then quantity end) as 7_one,
max(case when id=7 then quantity end) as 7_one,
max(case when id=10 then quantity end) as 10_ten from t
group by date