Get SUM of Current Week data and Current Year data from SQLite - sql

Question

I have a SQLite database and sales table is like the following,
| Id | quantity | dateTime |
------------------------------------
| 1 | 10 | 2019-12-25 12:55 |
| 2 | 05 | 2019-12-30 12:55 |
| 3 | 25 | 2020-08-23 12:55 |
| 4 | 25 | 2020-08-24 12:55 |
| 5 | 56 | 2020-08-25 12:55 |
| 6 | 25 | 2020-08-26 12:55 |
| 7 | 12 | 2020-08-27 12:55 |
| 8 | 30 | 2020-08-28 12:55 |
| 9 | 40 | 2020-08-29 12:55 |
I need to get the Current Week data (Mon to Sun) and the Current Year data from (Jan to Dec). So if I pass today date I need to get only the Current Week sales data group by days like the following,
If I pass today date and time (2020-08-28 13:55) the query should give me Current Week data like this,
Day Sold Items (SUM(quantity))
Monday 20
Tuesday 25
Wednesday 10
Thursday 50
Friday 60
Saturday 0 (If the date hasn't come yet I need to get 0)
Sunday 0
And same as the Current Year data when I pass the Current Date,
Month Sold Items (SUM(quantity))
JAN 20
FEB 25
MAR 10
APR 50
MAY 60
JUN 0 (If the month hasn't come yet I need to get 0)
JUL 0
... ...
I tried with multiple queries in SQLite but couldn't get what I need. Here are the queries I tried,
Weekly Data (This one gave me past week data also)
SELECT SUM(quantity) as quantity, strftime('%w', dateTime) as Day
From sales
Group by strftime('%w', dateTime)
Monthly Data
SELECT SUM(quantity) as quantity, strftime('%m', dateTime) as Month
From sales
Group by strftime('%m', dateTime)
So anybody can help me to achieve this? Thanks in advance.

Answer 1

For the totals of the current week you need a CTE that returns the names of the days and the another one that returns the Monday of the current week.
You must cross join these CTEs and left join your table to aggregate:
with
days as (
select 1 nr, 'Monday' day union all
select 2, 'Tuesday' union all
select 3, 'Wednesday' union all
select 4, 'Thursday' union all
select 5, 'Friday' union all
select 6, 'Saturday' union all
select 7, 'Sunday'
),
weekMonday as (
select date(
'now',
case when strftime('%w', 'now') <> '1' then '-7 day' else '0 day' end,
'weekday 1'
) monday
)
select d.day,
coalesce(sum(t.quantity), 0) [Sold Items]
from days d cross join weekMonday wm
left join tablename t
on strftime('%w', t.dateTime) + 0 = d.nr % 7
and date(t.dateTime) between wm.monday and date(wm.monday, '6 day')
group by d.nr, d.day
order by d.nr
For the totals of the current year you need a CTE that returns the month names and then left join the table to aggregate:
with
months as (
select 1 nr, 'JAN' month union all
select 2 nr, 'FEB' union all
select 3 nr, 'MAR' union all
select 4 nr, 'APR' union all
select 5 nr, 'MAY' union all
select 6 nr, 'JUN' union all
select 7 nr, 'JUL' union all
select 8 nr, 'AUG' union all
select 9 nr, 'SEP' union all
select 10 nr, 'OCT' union all
select 11 nr, 'NOV' union all
select 12 nr, 'DEC'
)
select m.month,
coalesce(sum(t.quantity), 0) [Sold Items]
from months m
left join tablename t
on strftime('%m', t.dateTime) + 0 = m.nr
and date(t.dateTime) between date('now','start of year') and date('now','start of year', '1 year', '-1 day')
group by m.nr, m.month
order by m.nr

Answer 2

You can use the below query to get the weekly date, I am assuming that everydate has single entry and hence not grouping otherwise you can add group by.
First we will get the weekly calendar based on the input date (I have taken current date)
and then left join with calendar to get the required sold items info.
WITH seq(n) AS
(
SELECT 0 UNION ALL SELECT n + 1 FROM seq
WHERE n < DATEDIFF(DAY, (SELECT DATEADD(DAY, 2 - DATEPART(WEEKDAY, GETDATE()), CAST(GETDATE() AS DATE)) [Week_Start_Date]), (Select DATEADD(DAY, 8 - DATEPART(WEEKDAY, GETDATE()), CAST(GETDATE() AS DATE)) [Week_End_Date]))
),
CALENDAR(d) AS
(
SELECT DATEADD(DAY, n, (SELECT DATEADD(DAY, 2 - DATEPART(WEEKDAY, GETDATE()), CAST(GETDATE() AS DATE)) [Week_Start_Date])) FROM seq
)
SELECT coalesce(QUANTITY, 0) sold_items ,DATENAME(WEEKDAY, d) week_day FROM CALENDAR a left outer join Table_WEEKDAY b
on (a.d = convert(date, b.dateTime))
ORDER BY d
OPTION (MAXRECURSION 0);

Answer 3

You can try the below - DEMO
select day,coalesce(sum(quantity),0) as quantity
from
(select 0 as day union all select 1 union all select 2 union all select 3 union all select 4
union all select 5 union all select 6) as d
left join sales on cast(strftime('%w', dateTime) as int)=day
group by strftime('%w', dateTime),day
order by day