I have a table which contains id (unique), system id, timestamp and status.
When status 1 it means, system unavailable, when 0 - available:
CREATE temp TABLE temp_data_test (
id int8 NULL,
system_id int8 NULL,
time timestamptz NULL,
status int4 NULL
);
INSERT INTO temp_data_test (id, system, time, status) VALUES
(53,1,'2022-04-02 13:57:07.000',1),
(54,1,'2022-04-02 14:10:26.000',0),
(55,1,'2022-04-02 14:28:45.000',1),
(56,1,'2022-04-02 14:32:19.000',0),
(57,1,'2022-04-05 03:20:18.000',1),
(58,3,'2022-04-05 03:21:18.000',1),
(59,2,'2022-04-05 03:21:22.000',1),
(60,2,'2022-04-06 02:27:15.000',0),
(61,3,'2022-04-06 02:27:15.000',0),
(62,1,'2022-04-06 02:28:17.000',0);
It works like when system become unavailable we get 1, when become available -> 0.
I need to get a result table when can see how much hours each day each system was unavailable.
For this table result should be
date system available unavailable
2022-04-02 1 13:57:07+00:18:19+09:27:40 =23:43:06 23:59:59-23:43:06=..
2022-04-02 2 24 0
2022-04-02 3 24 0
2022-04-03 1 24 0
2022-04-03 2 24 0
2022-04-03 3 24 0
...
2022-04-05 1 03:20:18 23:59:59-03:20:18=..
2022-04-05 3 03:21:18 23:59:59-03:21:18=..
2022-04-05 2 03:21:22 23:59:59-03:21:22=..
2022-04-06 1 23:59:59-02:28:17=.. 02:28:17
2022-04-06 3 23:59:59-02:27:15=.. 02:27:15
2022-04-06 2 23:59:59-02:27:15=.. 02:27:15
I try do it with over partition by and recursion, but get more interval, than I need.
I wrote a sample query for calculating intervals and showing intervals as hours using your table structure:
with d_test as (
select
row_number() over (order by system_id, time) as r_num,
"time"::date as "onlydate",
"time",
system_id,
status
from temp_data_test
order by system_id, time
)
select avi.*, unavi."unavialible", unavi."unavialible_hours" from (
select
d1.system_id,
d1.onlydate,
sum(d2.time - d1.time) as "avialible",
(extract(day from sum(d2.time - d1.time) )*24 + extract(hour from sum(d2.time - d1.time)))::text || ' hours' as "avialible_hours"
from d_test d1
inner join d_test d2 on d1.r_num+1 = d2.r_num and d1.system_id = d2.system_id
where d1.status = 1
group by d1.system_id, d1.onlydate
order by d1.system_id
) avi
left join (
select
d1.system_id,
d1.onlydate,
sum(d2.time - d1.time) as "unavialible",
(extract(day from sum(d2.time - d1.time) )*24 + extract(hour from sum(d2.time - d1.time)))::text || ' hours' as "unavialible_hours"
from d_test d1
inner join d_test d2 on d1.r_num+1 = d2.r_num and d1.system_id = d2.system_id
where d1.status = 0
group by d1.system_id, d1.onlydate
order by d1.system_id
) unavi on avi.system_id = unavi.system_id and avi.onlydate = unavi.onlydate
Result of this query:
system_id
onlydate
avialible
avialible_hours
unavialible
unavialible_hours
1
2022-04-02
00:16:53
0 hours
2 days 13:06:18
61 hours
1
2022-04-05
23:07:59
23 hours
2
2022-04-05
23:05:53
23 hours
3
2022-04-05
1 day 02:05:57
26 hours
Related
I have a table table1 which contains the details of any depositor like
Depositor
Deposit_Amount
Deposit_Date
Maturity_Date
Tenure
Rate
A
25000
2021-08-10
2022-08-10
12
10%
I have another table table2 which contains the interest due date as:
Interest_Due_Date
2021-09-30
2021-12-31
2022-03-31
2022-06-30
2022-08-10
My Code is:
with recursive recur (n, start_bal, days,principle,interest, end_bal) as
(
select sno,deposit_amount,rate,days,deposit_amount * (((rate::decimal(18,2))/100)/365)*days as interest, deposit_amount+(deposit_amount * (((rate::decimal(18,2))/100)/365)*days) as end_bal from (
SELECT
sno, COALESCE(DATE_PART('day', deposit_date::TIMESTAMP - lag(deposit_date::TIMESTAMP) over
(ORDER BY sno ASC rows BETWEEN UNBOUNDED PRECEDING AND CURRENT row)),0) AS
days, deposit_date, deposit_amount, rate
FROM
( SELECT
ROW_NUMBER () OVER (ORDER BY deposit_date) AS sno,
deposit_date,
deposit_amount,
rate
FROM
( SELECT
t1.deposit_date, t1.deposit_amount, t1.rate from table1 t1
UNION ALL
SELECT
t2.Interest_Due_Date AS idate, 0 as depo_amount, 0 as rate
FROM
table2 t2
ORDER BY
deposit_date) dep) calc) b where sno = 1 union all select b.sno, b.end_bal,b.days,b.prin_bal,(coalesce(a.end_bal,0)) * (((b.rate)/100)/365)*b.days as interest_NEW,
coalesce(a.end_bal,0)+ ((a.end_bal) * (((calc.rate)/100)/365)*calc.days) as end_bal_NEW
from b, recur as a
where calc.sno = a.n+1 ) select * from recur
"Every time when i try to execute the query its showing an error 'relation 'b' does not exist"
...
The result table should be
Deposit Amount
Date
Days
Interest
Total Amount
25000
2021-08-10
0
0
25000
0
2021-09-30
51
349.32
25349.32
0
2021-12-31
92
638.94
25988.26
0
2022-03-31
90
640.81
26629.06
0
2022-06-30
91
663.90
27292.97
0
2022-08-10
41
306.58
27599.54
I have 3 tables, a user table, an admin table, and a cust table. Both admin and cust tables are foreign keyed to the user_account table. Basically, every user has a user record, and the type of user they are is determined by if they have a record in the admin or the cust table.
user admin cust
user_id user_id | admin_id user_id | cust_id
--------- ---------|---------- ---------|---------
1 1 | a 2 | dd
2 4 | b 3 | ff
3
4
Then I have a login_history table that records the user_id and login timestamp every time a user logs into the app
login_history
user_id | login_on
---------|---------------------
1 | 2022-01-01 13:22:43
1 | 2022-01-02 16:16:27
3 | 2022-01-05 21:17:52
2 | 2022-01-11 11:12:26
3 | 2022-01-12 03:34:47
I would like to create a view that would contain all dates for the first day of each week in the year starting from jan 1st, and a count column that contains the count of unique admin users that logged in that week and a count of unique cust users that logged in that week. So the resulting view should contain the following 53 records, one for each week.
login_counts_view
week_start_date | admin_count | cust_count
-----------------|-------------|------------
2022-01-01 | 1 | 1
2022-01-08 | 0 | 2
2022-01-15 | 0 | 0
.
.
.
2022-12-31 | 0 | 0
Note that the first week (2022-01-01) only has 1 count for admin_count even though the admin with user_id 1 logged in twice that week.
Below is the current query I have for the view. However, the tables are pretty large and it takes over 10 seconds to retrieve all records from the view, mainly because of the left joined date comparisons.
CREATE VIEW login_counts_view AS
SELECT
week_start_dates.week_start_date::text AS week_start_date,
count(distinct a.user_id) AS admin_count,
count(distinct c.user_id) AS cust_count
FROM (
SELECT
to_char(i::date, 'YYYY-MM-DD') AS week_start_date
FROM
generate_series(date_trunc('year', NOW()), to_char(NOW(), 'YYYY-12-31')::date, '1 week') i
) week_start_dates
LEFT JOIN login_history l ON l.login_on::date BETWEEN week_start_dates.week_start_date::date AND (week_start_dates.week_start_date::date + INTERVAL '6 day')::date
LEFT JOIN admin a ON a.user_id = l.user_id
LEFT JOIN cust c ON c.user_id = l.user_id
GROUP BY week_start_date;
Does anyone have any tips as to how to make this query execute more efficiently?
Idea
Compute the pseudo-week of each login date: partition the year into 7-day slices and number them consecutively. The pseudo-week of a given date would be the ordinal number of the slice it falls into.
Then operate the joins on integers representing the pseudo-weeks instead of date values and comparisons.
Implementation
A view to implement this follows:
CREATE VIEW login_counts_view_fast AS
WITH RECURSIVE Numbers(i) AS ( SELECT 0 UNION ALL SELECT i + 1 FROM Numbers WHERE i < 52 )
SELECT CAST ( date_trunc('year', NOW()) AS DATE) + 7 * n.i week_start_date
, count(distinct lw.admin_id) admin_count
, count(distinct lw.cust_id) cust_count
FROM (
SELECT i FROM Numbers
) n
LEFT JOIN (
SELECT admin_id
, cust_id
, base
, pit
, pit-base delta
, (pit-base) / (3600 * 24 * 7) week
FROM (
SELECT a.user_id admin_id
, c.user_id cust_id
, CAST ( EXTRACT ( EPOCH FROM l.login_on ) AS INTEGER ) pit
, CAST ( EXTRACT ( EPOCH FROM date_trunc('year', NOW()) ) AS INTEGER ) base
FROM login_history l
LEFT JOIN admin a ON a.user_id = l.user_id
LEFT JOIN cust c ON c.user_id = l.user_id
) le
) lw
ON lw.week = n.i
GROUP BY n.i
;
Some remarks:
The epoch values are the number of seconds elapsed since an absolute base datetime (specifically 1/1/1970 0h00).
CASTS are necessary to convert doubles to integers and timestamps to dates as mandated by the signatures of postgresql date functions and in order to enforce integer arithmetics.
The recursive subquery is a generator of consecutive integers. It could possibly be replaced by a generate_series call (untested)
Evaluation
See it in action in this db fiddle
The query plan indicates savings of 50-70% in execution time.
I have a table which contains id (unique), number of system (system_id), timestamp time_change and status. When status 1 it means, system unavailable, when 0 - available:
CREATE temp TABLE temp_data_test (
id int8 NULL,
system_id int8 NULL,
time_change timestamptz NULL,
status int4 NULL
);
INSERT INTO temp_data_test (id, system_id, time_change, status) VALUES
(53,1,'2022-04-02 13:57:07.000',1),
(54,1,'2022-04-02 14:10:26.000',0),
(55,1,'2022-04-02 14:28:45.000',1),
(56,1,'2022-04-02 14:32:19.000',0),
(57,1,'2022-04-05 03:20:18.000',1),
(58,3,'2022-04-05 03:21:18.000',1),
(59,2,'2022-04-05 03:21:22.000',1),
(60,2,'2022-04-06 02:27:15.000',0),
(61,3,'2022-04-06 02:27:15.000',0),
(62,1,'2022-04-06 02:28:17.000',0);
And a table date_dict with date (just one column date_of_day date).
As you can see, status doesn't change everyday. But I need a statistics for each calendar day for each system.
So for day, that are not in the table I need add 2 rows for each system. First with timestamp 'date 00:00:00' and status opposite to first nearest status with a higher date (may be not in that day, but tomorrow).
And second with timestamp 'date 23:59:59' with opposite to nearest lower date (today, yesterday etc).
For this table I need something like
id system_id time_change status
63 1 '2022-04-02 00:00:00' 0
64 1 '2022-04-02 23:59:59' 1
65 1 '2022-04-03 00:00:00' 0
66 1 '2022-04-03 23:59:59' 1-- cause system was available from 2 april
67 1 '2022-04-04 00:00:00' 0
68 1 '2022-04-04 23:59:59' 1
69 1 '2022-04-05 00:00:00' 0
70 1 '2022-04-05 23:59:59' 0--cause become unavailable in 2022-04-05 03:20:18
And so on for another system
I suppose, it can be divide into 2 parts with first row and second (00:00:00 and 23:59:59). My attempts lead to null in dates and I try to group by date, which didn't work as I can see.
I have a table with messages and I need to find chats where were two or more messages in period of 10 seconds. table
id message_id time
1 1 2021.11.10 13:09:00
1 2 2021.11.10 13:09:01
1 3 2021.11.10 13:09:50
2 1 2021.11.10 15:18:00
2 2 2021.11.10 15:20:00
3 1 2021.11.12 15:00:00
3 2 2021.11.12 15:10:00
3 2 2021.11.12 15:10:10
So the result looks like
id
1
3
I can't come up with the idea how to group by a period or maybe it can be done other way?
select id
from t
group by id, ?
having count(message_id) > 1
You can join the table with itself, matching them on the chat id and your timeframe.
create table messages (chat_id integer,message_id integer,"time" timestamp);
insert into messages values
(1,1,'2021.11.10 13:09:00'),
(1,2,'2021.11.10 13:09:01'),
(1,3,'2021.11.10 13:09:50'),
(2,1,'2021.11.10 15:18:00'),
(2,2,'2021.11.10 15:20:00'),
(3,1,'2021.11.12 15:00:00'),
(3,2,'2021.11.12 15:10:00'),
(3,2,'2021.11.12 15:10:10');
select target_chat,
target_message,
count(*) "number of messages preceding by no more than 10 seconds"
from
(select t1.chat_id target_chat,
t1.message_id target_message,
t1.time,
t2.chat_id,
t2.message_id,
t2.time
from messages t1
inner join messages t2
on t1.chat_id=t2.chat_id
and t1.message_id<>t2.message_id
and (t2.time<=t1.time-'10 seconds'::interval and t2.time<=t1.time)) a
group by 1,2;
-- target_chat | target_message | number of messages preceding by no more than 10 seconds
---------------+----------------+---------------------------------------------------------
-- 1 | 3 | 2
-- 2 | 2 | 1
-- 3 | 2 | 2
--(3 rows)
From that you can select the records with your desired number of preceding messages.
this is a simple query that finds every previous value that is included in our interval
select id from test_table t where
t.time + interval '10 second' >=
(select time from test_table where id=t.id and time>t.time limit 1)
group by id;
results
id
----
1
3
To find rows within an period of time, you can tipically use a window function which avoids a self join on the table :
SELECT id, count(*) OVER (ORDER BY time RANGE BETWEEN CURRENT ROW AND '10 minutes' FOLLOWING)
FROM t
GROUP BY id
Then you can use this query as a sub-query if you only want the id with count(*) > 1 :
SELECT DISTINCT ON (l.id) l.id
FROM
( SELECT id, count(*) OVER (ORDER BY time RANGE BETWEEN CURRENT ROW AND '10 minutes' FOLLOWING) AS ct
FROM t
GROUP BY id
) AS l
WHERE l.ct > 1 ;
I want to get a table that constructs a column that tracks how many times an id appears in a given week. If the id appears once it is given a 1, if it appears twice it is given a 2, but if it appears more than two times it is given a 0.
id date
a 2015-11-10
a 2015-11-25
a 2015-11-09
b 2015-11-10
b 2015-11-09
a 2015-11-05
b 2015-11-23
b 2015-11-28
b 2015-12-04
a 2015-11-10
b 2015-12-04
a 2015-12-07
a 2015-12-09
c 2015-11-30
a 2015-12-06
c 2015-10-31
c 2015-11-04
b 2015-12-01
a 2015-10-30
a 2015-12-14
the one week intervals are given as follows
1 - 2015-10-30 to 2015-11-05
2 - 2015-11-06 to 2015-11-12
3 - 2015-11-13 to 2015-11-19
4 - 2015-11-20 to 2015-11-26
5 - 2015-11-27 to 2015-12-03
6 - 2015-12-04 to 2015-12-10
7 - 2015-12-11 to 2015-12-17
The table should look like this.
id interval count
a 1 2
b 1 0
c 1 2
a 2 0
b 2 2
c 2 0
a 3 0
b 3 0
c 3 0
a 4 1
b 4 1
c 4 0
a 5 0
b 5 2
c 5 1
a 6 0
b 6 2
c 6 0
a 7 1
b 7 0
c 7 0
The interval column doesn't have to be there, I simply added it for clarity.
I am new to sql and am unsure how to break the dates into intervals. The only thing I have is grouping by date and counting.
Select id ,date, count (*) as frequency
from data_1
group by id, date having frequency <= 2;
Looking at just the data you provided, this does the trick:
SELECT v.id,
i.interval,
coalesce((CASE WHEN sub.cnt < 3 THEN sub.cnt ELSE 0 END), 0) AS count
FROM (VALUES('a'), ('b'), ('c')) v(id)
CROSS JOIN generate_series(1, 7) i(interval)
LEFT JOIN (
SELECT id, ((date - '2015-10-30')/7 + 1)::int AS interval, count(*) AS cnt
FROM my_table
GROUP BY 1, 2) sub USING (id, interval)
ORDER BY 2, 1;
A few words of explanation:
You have three id values which are here recreated with a VALUES clause. If you have many more or don't know beforehand which id's to enumerate, you can always replace the VALUES clause with a sub-query.
You provide a specific date range over 7 weeks. Since you might have weeks where a certain id is not present you need to generate a series of the interval values and CROSS JOIN that to the id values above. This yields the 21 rows you are looking for.
Then you calculate the occurrences of ids in intervals. You can subtract a date from another date which will give you the number of days in between. So subtract the date of the row from the earliest date, divide that by 7 to get the interval period, add 1 to make the interval 1-based and convert to integer. You can then convert counts of > 2 to 0 and NULL to 0 with a combination of CASE and coalesce().
The query outputs the interval too, otherwise you will have no clue what the data refers to. Optionally, you can turn this into a column which shows the date range of the interval.
More flexible solution
If you have more ids and a larger date range, you can use the below version which first determines the distinct ids and the date range. Note that the interval is now 0-based to make calculations easier. Not that it matters much because instead of the interval number, the corresponding date range is displayed.
WITH mi AS (
SELECT min(date) AS min, ((max(date) - min(date))/7)::int AS intv FROM my_table)
SELECT v.id,
to_char((mi.min + i.intv * 7)::timestamp, 'YYYY-mm-dd') || ' - ' ||
to_char((mi.min + i.intv * 7 + 6)::timestamp, 'YYYY-mm-dd') AS period,
coalesce((CASE WHEN sub.cnt < 3 THEN sub.cnt ELSE 0 END), 0) AS count
FROM mi,
(SELECT DISTINCT id FROM my_table) v
CROSS JOIN LATERAL generate_series(0, mi.intv) i(intv)
LEFT JOIN LATERAL (
SELECT id, ((date - mi.min)/7)::int AS intv, count(*) AS cnt
FROM my_table
GROUP BY 1, 2) sub USING (id, intv)
ORDER BY 2, 1;
SQLFiddle with both solutions.
Assuming you have a table of all users, this will do the trick.
select
users.id,
interval_table.id,
CASE
WHEN count(log_table.user_id)>2 THEN 0
ELSE count(log_table.user_id)
END
from users
cross join interval_table
left outer join log_table
on users.id = log_table.user_id
and log_table.event_date >= interval_table.start_interval
and log_table.event_date < interval_table.stop_interval
group by users.id, interval_table.id
order by interval_table.id, users.id
Check it out: http://sqlfiddle.com/#!15/1a822/21