I can unify the two select below in a single, where in the first column return the result of the first and second column the result of the second.
select count(*) from rrhh.empleado where fecha_contratado > current_date - interval '100 days'; // select1
select count(*) from rrhh.empleado where fecha_fin_contrato > current_date - interval '100 days'; //select2
Thank you
try:
with a as (
select
case when fecha_contratado > current_date - interval '100 days' then 1
else 0 end q1
, case when fecha_fin_contrato > current_date - interval '100 days' then 1
else 0 end q2
from rrhh.empleado
)
select sum(q1), sum(q2)
from a
;
This is a typical case for conditional aggregation:
select count(*) filter (where fecha_contratado > current_date - interval '100 days'),
count(*) filter (where fecha_fin_contrato > current_date - interval '100 days')
from rrhh.empleado
You can use the CASE expression (and the fact that most aggregates does not use NULL values) for versions earlier than 9.4:
select count(case when fecha_contratado > current_date - interval '100 days' then 1 end),
count(case when fecha_fin_contrato > current_date - interval '100 days' then 1 end)
from rrhh.empleado
Note: these queries will scan the whole table, while your original queries could make use of indexes on fecha_contratado and fecha_fin_contrato. If performance matters to you, you could append a filter to these queries too:
where least(fecha_contratado, fecha_fin_contrato) > current_date - interval '100 days'
and you could index the expression: least(fecha_contratado, fecha_fin_contrato).
Related
I have a query below to query max and min of day interval in a range of time ( current_date - 2 to current_date - 1). Now, I need to query dayshift and extra shift separately ( dayshift from 5am to 3pm, extra shift will be the remains).
select sum(gap) from (
select to_char(time_stamp, 'yyyy/mm/dd') as day,
EXTRACT(EPOCH FROM (max(time_stamp) - min(time_stamp))) /3600 as gap
from group_table_debarker
where time_stamp >= (current_date - 2)
and time_stamp <= (current_date - 1)
and to_char(time_stamp, 'hh:mi') > '03:00' and to_char(time_stamp, 'hh:mi') < '15:00'
group by to_char(time_stamp, 'yyyy/mm/dd')
) as xxx
select sum(gap) from (
select to_char(time_stamp, 'yyyy/mm/dd') as day,
EXTRACT(EPOCH FROM (max(time_stamp) - min(time_stamp))) /3600 as gap
from group_table_debarker
where time_stamp >= (current_date - 2)
and time_stamp <= (current_date - 1)
and to_char(time_stamp, 'hh:mi') > '03:00' and to_char(time_stamp, 'hh:mi') < '15:00'
group by to_char(time_stamp, 'yyyy/mm/dd')
) as xxx
I've tried this but result wasn't expected
This is a syntax error, but didn't see what the correct syntax would be.
The goal is to handle the case where days is null.
SELECT * FROM tbl WHERE created_at > current_date - INTERVAL 'COALESCE(%days%, 999) DAY'
You can multiply COALESCE(%days%, 999) to an interval of 1 day:
SELECT * FROM tbl
WHERE created_at > current_date - COALESCE(%days%, 999) * INTERVAL '1 DAY'
Use make_interval()
SELECT *
FROM tbl
WHERE created_at > current_date - make_interval(days:=COALESCE(%days%, 999));
I compare results from two selects and get 1 or 0 as a final result.
Below query syntax is good but this query causes timeout.
SELECT (CASE WHEN (
select count(*) from order where ordered_date > (NOW() - INTERVAL '120 minutes')
and order_ordered = current_date) >
(select count(*)/3
from order
where ordered_date > (NOW() - INTERVAL '2 days' - INTERVAL '120 minutes')
and ordered_date < (NOW() - INTERVAL '2 days'))
THEN 1 ELSE 0 end);
Therefore, i try to optimize the query to use an alias for each select as below :
select (case when a > b then 1 else 0 end) from (select count(*) from order where ordered_date > (NOW() - INTERVAL '120 minutes')
and order_ordered = current_date) as a,
from (select count(*)/3
from order
where ordered_date > (NOW() - INTERVAL '2 days' - INTERVAL '120 minutes')
and ordered_date < (NOW() - INTERVAL '2 days'))as b;
I have syntax error near "from", in my memory this kind of syntax works on mysql.
Could you please advise me if there a possiblity to use two times of "from" by using alias on Postgresql or if you know another possility i am a taker.
Sample:
First query gives : select count(*) from order where ordered_date > (NOW() - INTERVAL '120 minutes') and order_ordered = current_date -> 60
Seconde query gives : select count(*)/3 from order where ordered_date > (NOW() - INTERVAL '2 days' - INTERVAL '120 minutes') and ordered_date < (NOW() - INTERVAL '2 days') -> 20
Final condition : case when (60 > 20 then 1 else 0 end)
Result expected : 1
Thanks
I suggest using SELECT in WITH (here documentation).
WITH orders_current_date AS (
SELECT count(*)
FROM order
WHERE ordered_date > (NOW() - INTERVAL '120 minutes')
AND order_ordered = current_date)
), orders_interval AS (
SELECT count(*)/3
FROM order
WHERE ordered_date > (NOW() - INTERVAL '2 days' - INTERVAL '120 minutes')
AND ordered_date < (NOW() - INTERVAL '2 days')
)
SELECT
CASE
WHEN SELECT * FROM orders_current_date > SELECT * FROM orders_interval
THEN '1'
ELSE
0
END;
I have two sets of data, one of which is dynamically generated.
If I leave off the column state it works perfectly as that column doesn't really exist, my question is how can I ignore a column for the UNION so that it combines the two datasets (as it is it's the same as UNION ALL). eg I prefer the first table and want any rows from the second dataset ignored if they exist in the first one.
SELECT event_id, start_at, state
FROM event_logs
WHERE start_at BETWEEN current_date AND current_date + interval '3 weeks'
UNION
SELECT id event_id,
GENERATE_SERIES(date_trunc('week', current_date)::date + (extract(isodow from start_at)::int - 1) + start_at::time, current_date + interval '3 weeks', '1 week'::INTERVAL) AS start_at,
'draft' AS state
FROM events
Update, also tried:
WITH future_logs AS (
SELECT id event_id,
GENERATE_SERIES(date_trunc('week', current_date)::date + (extract(isodow from start_at)::int - 1) + start_at::time, current_date + interval '3 weeks', '1 week'::INTERVAL) AS start_at,
'draft' AS state
FROM events)
SELECT future_logs.event_id, future_logs.start_at, future_logs.state
FROM future_logs
LEFT JOIN event_logs ON future_logs.event_id = event_logs.event_id AND future_logs.start_at = event_logs.start_at
WHERE event_logs.start_at BETWEEN current_date AND current_date + interval '3 weeks'
But got too few results 77 vs ~1000 expected.
Just add NOT EXISTS() to the second leg, and you can use UNION ALL to avoid sort/merging.
SELECT event_id, start_at, state
FROM event_logs
WHERE start_at BETWEEN current_date AND current_date + interval '3 weeks'
UNION ALL
SELECT id AS event_id
, generate_series(date_trunc('week', current_date)::date + (extract(isodow from start_at)::int - 1) + start_at::time
, current_date + interval '3 weeks'
, '1 week'::INTERVAL) AS start_at
, 'draft' AS state
FROM events ev
WHERE NOT EXISTS ( SELECT*
FROM event_logs nx
WHERE nx.event_id =ev.id
AND nx.start_at BETWEEN current_date AND current_date + interval '3 weeks' )
;
select DISTINCT ON (date_day) date_day, state from(
SELECT day::date as date_day, null as state
FROM generate_series(now()- interval '2 week'
, now()
, interval '1 day') day
UNION ALL
select distinct
date_trunc('day',e.updated_at) as date_day,
max(des.state) over (partition by date_trunc('day',des.updated_at)) as state
from device_event as des where e.id=49 and e.updated_at >= now() - interval '2 week'
) dba order by 1
I would add one other column taborder into your UNION query to ensure simple ordering of the rows and use window function row_number() over(...) in following way:
SELECT
event_id,
start_at,
state
FROM (
SELECT
event_id,
start_at,
state,
row_number(*) OVER (PARTITION BY event_id, start_at ORDER BY taborder) AS rownum
FROM (
SELECT
event_id,
start_at,
state,
1 AS taborder
FROM original_table
UNION
SELECT
event_id,
start_at,
state,
2 AS taborder
FROM draft_table
) src0
) src1
WHERE rownum = 1
ORDER BY 1, 2, 3
I have a server with PostgreSQL 8.4 which is being rebooted every night at 01:00 (don't ask) and need to get a list of connected users (i.e. their timestamps are u.login > u.logout):
SELECT u.login, u.id, u.first_name
FROM pref_users u
WHERE u.login > u.logout and
u.login > now() - interval '24 hour'
ORDER BY u.login;
login | id | first_name
----------------------------+----------------+-------------
2012-03-14 09:27:33.41645 | OK171511218029 | Alice
2012-03-14 09:51:46.387244 | OK448670789462 | Bob
2012-03-14 09:52:36.738625 | OK5088512947 | Sergej
But comparing u.login > now()-interval '24 hour' also delivers the users before the last 01:00, which is bad, esp. in the mornings.
Is there any efficient way to get the logins since the last 01:00 without doing string acrobatics with to_char()?
This should be 1) correct and 2) as fast as possible:
SELECT u.login, u.id, u.first_name
FROM pref_users u
WHERE u.login >= now()::date + interval '1h'
AND u.login > u.logout
ORDER BY u.login;
As there are no future timestamps in your table (I assume), you need no upper bound.
Some equivalent expressions:
SELECT localtimestamp::date + interval '1h'
, current_date + interval '1h'
, date_trunc('day', now()) + interval '1h'
, now()::date + interval '1h'
now()::date used to perform slightly faster than CURRENT_DATE in older versions, but that's not true any more in modern Postgres. But either is still faster than LOCALTIMESTAMP in Postgres 14 for some reason.
date_trunc('day', now()) + interval '1h' slightly differs in that it returns timestamptz. But it is coerced to timestamp according to the timezone setting of the current session in comparison to the timestamp column login, doing effectively the same.
See:
Ignoring time zones altogether in Rails and PostgreSQL
To return rows for the previous day instead of returning nothing when issued between 00:00 and 01:00 local time, use instead:
WHERE u.login >= (LOCALTIMESTAMP - interval '1h')::date + interval '1h'
select * from termin where DATE(dateTimeField) >= CURRENT_DATE AND DATE(dateTimeField) < CURRENT_DATE + INTERVAL '1 DAY'
This works for me - it selects ALL rows with todays Date.
select * from termin where DATE(dateTimeField) = '2015-11-17'
This works well for me!
An easy way of getting only time stamps for the current day since 01:00 is to filter with
CURRENT_DATE + interval '1 hour'
So your query should look like this:
SELECT u.login, u.id, u.first_name
FROM pref_users u
WHERE u.login > u.logout AND
u.login > CURRENT_DATE + interval '1 hour'
ORDER BY u.login;
Hope that helps.
where
u.login > u.logout
and
date_trunc('day', u.login) = date_trunc('day', now())
and
date_trunc('hour', u.login) >= 1
All answers so far are incorrect because they give the wrong answer between 0.00 and 1.00. So if you happen to run the query in that time period you get no results. Based on #ErwinBrandstetter's answer, what you want is this:
WHERE u.login > u.logout
AND u.login >= CASE WHEN NOW()::time < '1:00'::time THEN NOW()::date - INTERVAL '23 HOUR' ELSE NOW()::date + INTERVAL '1 HOUR' END;
I would love to do without the conditional but found no way to.
Edit: #ErwinBrandstetter did do it without a conditional, leaving this here for completeness.