I have a table with some columns. Unfortunately, I don't have column with classic date format like "YYYY-MM-DD".
I have columns year and month, like:
2021 | 7
2021 | 10
2021 | 1
I want to build date from these columns and extract quarter in format (Q3'21) from this date. Can I do it with PostgreSQL?
I expect two new columns date and quarter:
2021 | 7 | 2021-07-01 | Q3'21
2021 | 10 | 2021-10-01 | Q4'21
2021 | 1 | 2021-01-01 | Q1'21
I tried to build date with simple concatenation gr."year" || '-0' || gr."month" || '-01' as custom_date, but i got wrong values like:
2021-010-01
You an use make_date() to create a date, then use to_char() to format that date:
select t.year,
t.month,
make_date(t.year, t.month, 1),
to_char(make_date(t.year, t.month, 1), '"Q"Q''YY')
from the_table t;
Use MAKE_DATE:
select
year, month,
make_date(year, month, 1) as first_day_of_month,
'Q' || to_char(make_date(year, month, 1), 'Q') || '''' ||
to_char(make_date(year, month, 1), 'YY') as quarter
from mytable;
Related
I have table which stores person, start of holiday and stop of holiday.
I need to count from it, how many working days per month person was on holiday. So I want to partition this table over month.
To get holidays I'm using: https://github.com/christopherthompson81/pgsql_holidays
Let's assume I have table for one person only with start/stop only.
create table data (id int, start date, stop date);
This is function for network_days I wrote:
CREATE OR REPLACE FUNCTION network_days(start_date date , stop_date date) RETURNS bigint AS $$
SELECT count(*) FROM
generate_series(start_date , stop_date - interval '1 minute' , interval '1 day') the_day
WHERE
extract('ISODOW' FROM the_day) < 6 AND the_day NOT IN (
SELECT datestamp::timestamptz FROM holidays_poland (extract(year FROM o.start_date)::int, extract(year FROM o.stop_date)::int))
$$
LANGUAGE sql
STABLE;
and I created function with query like:
--$2 = 2020
SELECT
month, year, sum(value_per_day)
FROM (
SELECT to_char(dt , 'mm') AS month, to_char(dt, 'yyyy') AS year, (network_days ((
CASE WHEN EXTRACT(year FROM df.start_date) < 2020 THEN (SELECT date_trunc('year' , df.start_date) + interval '1 year')::date
ELSE df.start_date END) , ( CASE WHEN EXTRACT(year FROM df.stop_date) > $2 THEN (date_trunc('year' , df.stop_date))::date
ELSE
df.stop_date END))::int ::numeric / count(*) OVER (PARTITION BY id))::int AS value_per_day
FROM intranet.dayoff df
LEFT JOIN generate_series((
CASE WHEN EXTRACT(year FROM df.start_date) < $2 THEN (SELECT date_trunc('year' , df.start_date) + interval '1 year')::date ELSE df.start_date
END) , (CASE WHEN EXTRACT(year FROM df.stop_date) > $2 THEN (date_trunc('year' , df.stop_date))::date
ELSE df.stop_date END) - interval '1 day' , interval '1 day') AS t (dt) ON extract('ISODOW' FROM dt) < 6
WHERE
extract(isodow FROM dt) < 6 AND (EXTRACT(year FROM start_date) = $2 OR EXTRACT(year FROM stop_date) = $2)) t
GROUP BY month, year
ORDER BY month;
based on: https://dba.stackexchange.com/questions/237745/postgresql-split-date-range-by-business-days-then-aggregate-by-month?rq=1
and I almost have it:
10 rows returned
| month | year | sum |
| ----- | ---- | ---- |
| 03 | 2020 | 2 |
| 04 | 2020 | 13 |
| 06 | 2020 | 1 |
| 11 | 2020 | 1 |
| 12 | 2020 | 2 |
| 05 | 2020 | 1 |
| 10 | 2020 | 2 |
| 08 | 2020 | 10 |
| 01 | 2020 | 1 |
| 02 | 2020 | 1 |
so in function I created I'd need to add something like this
dt NOT IN (SELECT datestamp::timestamptz FROM holidays_poland ($2, $2))
but I end up with many conditions and I feel like this wrong approach.
I feel like I should just somehow divide table from:
id start stop
1 31.12.2019 00:00:00 01.01.2020 00:00:00
2 30.03.2020 00:00:00 14.04.2020 00:00:00
3 01.05.2020 00:00:00 03.05.2020 00:00:00
to
start stop
30.03.2020 00:00:00 01.01.2020 00:00:00
01.01.2020 00:00:00 14.04.2020 00:00:00
01.05.2020 00:00:00 03.05.2020 00:00:00
and just run network_days function for this date range, but I couldn't successfully partition my query of the table to get such result.
What do you think is best way to achieve what I want to calculate?
demo:db<>fiddle
SELECT
gs::date
FROM person_holidays p,
generate_series(p.start, p.stop, interval '1 day') gs -- 1
WHERE gs::date NOT IN (SELECT holiday FROM holidays) -- 2
AND EXTRACT(isodow from gs::date) < 6 -- 3
Generate date series from person's start and stop date
Exclude all dates from the holidays table
If necessary: Exclude all weekend days (Saturday and Sunday)
Afterwards you are able to GROUP BY months and count the records:
SELECT
date_trunc('month', gs),
COUNT(*)
FROM person_holidays p,
generate_series(p.start, p.stop, interval '1 day') gs
WHERE gs::date NOT IN (SELECT holiday FROM holidays)
and extract(isodow from gs::date) < 6
GROUP BY 1
I have some values that represent years.
For example 37,8 years.
I want to convert it in SQL Oracle to Three columns:
Year: 37
Month: 9
Days: 18
How can I do that in my query?
select
trunc(n) as years
,to_char(date'2020-01-01' + mod(n,1)*365, 'mm') as months
,to_char(date'2020-01-01' + mod(n,1)*365, 'dd') as days
from (select 37.8 n from dual);
YEARS MONTHS DAYS
37 10 19
You can use EXTRACT to get the values:
SELECT EXTRACT( YEAR FROM dt ) - 1970 AS years,
EXTRACT( MONTH FROM dt ) - 1 AS months,
EXTRACT( DAY FROM dt ) - 1 AS days
FROM (
SELECT DATE '1970-01-01' + 37.8 * 365.25 AS dt
FROM DUAL
)
Which outputs:
YEARS | MONTHS | DAYS
----: | -----: | ---:
37 | 9 | 19
db<>fiddle here
I need to group my dates as Quarters, April to June as Q1, Jul to Sep as Q2, Oct to Dec as Q3 and Jan to March as Q4
I need to add another column besides close_dates showing Quarters. I cannot find any date function i can use.
Any ideas on this.
You can extract the month part and use a case expression:
select
close_date,
case
when 0 + strftime('%m', close_date) between 1 and 3 then 'Q4'
when 0 + strftime('%m', close_date) between 4 and 6 then 'Q1'
when 0 + strftime('%m', close_date) between 7 and 9 then 'Q2'
when 0 + strftime('%m', close_date) between 10 and 12 then 'Q3'
end as quarter
from mytable
The addition of 0 is there to force the conversion of the result of strftime() to a number.
This could also be expressed using date artihmetics (which lets you generate the fiscal year too):
select
close_date,
strftime('%Y', close_date, '-3 months')
|| 'Q' || ((strftime('%m', close_date, '-3 months') - 1) / 4) as year_quarter
from mytable
The format of your dates is not YYYY-MM-DD which is the only valid date format for SQLite.
So if you want to extract the month of a date, any date function that SQLite supports will fail.
You must use the string function SUBSTR() to extract the month and then other functions like NULLIF() and COALESCE() to adjust the quarter to your requirement.
Assuming that the format of your dates is DD/MM/YYYY:
SELECT Close_Date,
'Q' || COALESCE(NULLIF((SUBSTR(Close_Date, 4, 2) - 1) / 3, 0), 4) AS Quarter
FROM tablename
If the format is MM/DD/YYYY then change SUBSTR(Close_Date, 4, 2) to SUBSTR(Close_Date, 1, 2) or just Close_Date because SQLite will implicitly convert the date to a number which will be the starting digits of the date.
See the demo.
Results:
> Close_Date | Quarter
> :--------- | :------
> 01/04/2019 | Q1
> 01/05/2019 | Q1
> 01/10/2019 | Q3
> 01/09/2019 | Q2
> 01/06/2019 | Q1
> 01/09/2019 | Q2
> 01/04/2019 | Q1
> 01/07/2019 | Q2
I would do it with arithmetic rather than a case expression:
select floor( (strftime('%m', close_date) + 2) / 3 ) as quarter
I have a set of data from a table that would only be populated if a user has data for a certain month just like this:
Month | MonthName | Value
3 | March | 136.00
4 | April | 306.00
7 | July | 476.00
12 | December | 510.48
But what I need is to check if a month is skipped then adding the value the month before so the end result would be like this:
Month | MonthName | Value
3 | March | 136.00
4 | April | 306.00
5 | May | 306.00 -- added data
6 | June | 306.00 -- added data
7 | July | 476.00
8 | August | 476.00 -- added data
9 | September | 476.00 -- added data
10 | October | 476.00 -- added data
11 | November | 476.00 -- added data
12 | December | 510.48
How can I do this dynamically on SQL Server?
One method is a recursive CTE:
with cte as (
select month, value, lead(month) over (order by month) as next_month
from t
union all
select month + 1, value, next_month
from cte
where month + 1 < next_month
)
select month, datename(month, datefromparts(2020, month, 1)) as monthname, value
from cte
order by month;
Here is a db<>fiddle.
you can use spt_values to get continuous number 1-12, and then left join your table by max(month)
select t1.month
,datename(month,datefromparts(2020, t1.month, 1)) monthname
,t2.value
from (
select top 12 number + 1 as month from master..spt_values
where type = 'p'
) t1
left join t t2 on t2.month = (select max(month) from t tmp where tmp.month < = t1.month)
where t2.month is not null
CREATE TABLE T
([Month] int, [MonthName] varchar(8), [Value] numeric)
;
INSERT INTO T
([Month], [MonthName], [Value])
VALUES
(3, 'March', 136.00),
(4, 'April', 306.00),
(7, 'July', 476.00),
(12, 'December', 510.48)
;
Demo Link SQL Server 2012 | db<>fiddle
note
if you have year column then you need to fix the script.
I have data like this:
id | start_date | end_date
----------------------------
1 | 16-09-2019 | 22-12-2019
I want to get the following results:
id | month | year | days
------------------------
1 | 09 | 2019 | 15
1 | 10 | 2019 | 31
1 | 11 | 2019 | 30
1 | 12 | 2019 | 22
Is there a way to get that result ?
This is what you want to do:
SELECT id, EXTRACT(MONTH FROM start_date ) as month , EXTRACT(YEAR FROM start_date ) as year , DATEDIFF(end_date, start_date ) as days
From tbl
You can use MONTH() , YEAR() and DATEDIFF() functions
SELECT id, MONTH(start_date) as month, YEAR(start_date ) as year, DATEDIFF(end_date, start_date ) as days from table-name
One way is to create a Calendar table and use that.
select month,year, count(*)
from Calendar
where db_date between '2019-09-16'
and '2019-12-22'
group by month,year
CHECK DEMO HERE
Also you can use recursive CTE to achieve the same.
You can use a recursive CTE and aggregation:
with recursive cte as (
select id, start_date, end_date
from t
union all
select id, start_date + interval 1 day, end_date
from cte
where start_date < end_date
)
select id, year(start_date), month(start_date), count(*) as days
from cte
group by id, year(start_date), month(start_date);
Here is a db<>fiddle.