count consecutive number of -1 in a column. count >=14 - sql

I'm trying to figure out query to count "-1" that have occurred for more than 14 times. Can anyone help me here. I tried everything from lead, row number, etc but nothing is working out.
The BP is recorded for every minute and I need to figure the id's who's bp_level was "-1" for more than 14min

You may try the following:
Select Distinct B.Person_ID, B.[Consecutive]
From
(
Select D.person_ID, COUNT(D.bp_level) Over (Partition By D.grp, D.person_ID Order By D.Time_) [Consecutive]
From
(
Select Time_, Person_ID, bp_level,
DATEADD(Minute, -ROW_NUMBER() Over (Partition By Person_ID Order By Time_), Time_) grp
From mytable Where bp_level = -1
) D
) B
Where B.[Consecutive] >= 14
See a demo from db<>fiddle. Using SQL Server.
DATEADD(Minute, -ROW_NUMBER() Over (Partition By Person_ID Order By Time_), Time_): to define a unique group for consecutive times per person, where (bp_level = -1).
COUNT(D.bp_level) Over (Partition By D.grp, D.person_ID Order By D.Time_): to find the cumulative sum of bp_level over the increasing of time for each group.
Once a none -1 value appeared the group will split into two groups and the counter will reset to 0 for the other group.
NOTE: this solution works only if there are no gaps between the consecutive times, the time is increased by one minute for each row/ person, otherwise, the query will not work but can be modified to cover the gaps.

with data as (
select *,
count(case when bp_level = 1 then 1 end) over
(partition by person_id order by time) as grp
from T
)
select distinct person_id
from data
where bp_level = -1
group by person_id, grp
having count(*) > 14; /* = or >= ? */
If you want to rely on timestamps rather than a count of rows then you could use the time difference:
...
-- where 1 = 1 /* all rows */
group by person_id, grp
having datediff(minute, min(time), max(time)) > 14;
The accepted answer would have issues with scenarios where there are multiple rows with the same timestamp if there's any potential for that to happen.
https://dbfiddle.uk/?rdbms=sqlserver_2019&fiddle=2ad6a1b515bb4091efba9b8831e5d579

Related

How can i group rows on sql base on condition

I am using redshift sql and would like to group users who has overlapping voucher period into a single row instead (showing the minimum start date and max end date)
For E.g if i have these records,
I would like to achieve this result using redshift
Explanation is tat since row 1 and row 2 has overlapping dates, I would like to just combine them together and get the min(Start_date) and max(End_Date)
I do not really know where to start. Tried using row_number to partition them but does not seem to work well. This is what I tried.
select
id,
start_date,
end_date,
lag(end_date, 1) over (partition by id order by start_date) as prev_end_date,
row_number() over (partition by id, (case when prev_end_date >= start_date then 1 else 0) order by start_date) as rn
from users
Are there any suggestions out there? Thank you kind sirs.
This is a type of gaps-and-islands problem. Because the dates are arbitrary, let me suggest the following approach:
Use a cumulative max to get the maximum end_date before the current date.
Use logic to determine when there is no overall (i.e. a new period starts).
A cumulative sum of the starts provides an identifier for the group.
Then aggregate.
As SQL:
select id, min(start_date), max(end_date)
from (select u.*,
sum(case when prev_end_date >= start_date then 0 else 1
end) over (partition by id
order by start_date, voucher_code
rows between unbounded preceding and current row
) as grp
from (select u.*,
max(end_date) over (partition by id
order by start_date, voucher_code
rows between unbounded preceding and 1 preceding
) as prev_end_date
from users u
) u
) u
group by id, grp;
Another approach would be using recursive CTE:
Divide all rows into numbered partitions grouped by id and ordered by start_date and end_date
Iterate over them calculating group_start_date for each row (rows which have to be merged in final result would have the same group_start_date)
Finally you need to group the CTE by id and group_start_date taking max end_date from each group.
Here is corresponding sqlfiddle: http://sqlfiddle.com/#!18/7059b/2
And the SQL, just in case:
WITH cteSequencing AS (
-- Get Values Order
SELECT *, start_date AS group_start_date,
ROW_NUMBER() OVER (PARTITION BY id ORDER BY start_date, end_date) AS iSequence
FROM users),
Recursion AS (
-- Anchor - the first value in groups
SELECT *
FROM cteSequencing
WHERE iSequence = 1
UNION ALL
-- Remaining items
SELECT b.id, b.start_date, b.end_date,
CASE WHEN a.end_date > b.start_date THEN a.group_start_date
ELSE b.start_date
END
AS groupStartDate,
b.iSequence
FROM Recursion AS a
INNER JOIN cteSequencing AS b ON a.iSequence + 1 = b.iSequence AND a.id = b.id)
SELECT id, group_start_date as start_date, MAX(end_date) as end_date FROM Recursion group by id, group_start_date ORDER BY id, group_start_date

How to select specific rows in a "group by" groups using conditions on multiple columns?

I have the following table with many userId (in the example only one userId for demo purpose):
For every userId I want to extract two rows:
The first row should be isTransaction = 0 and the earliest date!
The second row should be isTransaction = 1, device should be different from that of the first row, isTransaction should be equal to 1 and the earliest date right after that of the first row
That is, the output should be:
Time userId device isTransaction
2021-01-27 10187675 mobile 0
2021-01-30 10187675 web 1
I tried to rank rows with partitioning and ordering but it didn't work:
Select * from
(SELECT *, rank() over(partition by userId, device, isTransaction order by isTransaction, Time) as rnk
FROM table 1)
where rnk=1
order by Time
Please help! It would be also good to check the time difference between these two rows to not exceed 30 days. Otherwise, userId should be dropped.
You can first identify the earliest time for 0. Then enumerate the rows and take only the first one:
select t.*
from (select t.*,
row_number() over (partition by userid, status order by time) as seqnum
from (select t.*,
min(case when isTransaction = 0 then time end) over (partition by userid order by time) as time_0
from t
) t
where time > time_0
) t
where seqnum = 1;
This satisfies the two conditions you enumerated.
Then buried in the text, you want to eliminate rows where the difference is greater than 30 days. That is a little tricker . . . but not too hard:
select t.*
from (select t.*,
min(case when isTransaction = 1 then time end) over (partition by userid) as time_1
row_number() over (partition by userid, status order by time) as seqnum
from (select t.*,
min(case when isTransaction = 0 then time end) over (partition by userid order by time) as time_0
from t
) t
where time > time_0
) t
where seqnum = 1 and
time_1 < timestamp_add(time_0, interval 30 day);

SQL count new values only with partition by - running count with no duplicates

Based on table below in Presto I need a column for all new 'rid'. What I managed to do is the same what I can achieve with partition by but it's not exactly what I'm looking for (db<>fiddle demo).
Goal is to have many groupings counts but I think this should describe problem sufficiently.
I need data truncated by days and column for new users every day as shown at example below. In simple words - if value repeats don't count it. I've tried to find correlation between this and relational division problem but I just stuck.
You could use row_number() to rank the records of each rid by time; then you can aggregate and count in only the top record per group.
select
date_trunc(day, t.time) dy,
count(*) rid_count,
sum(case when t.rn = 1 then 1 else 0 end) new_rid_count
from (
select
t.*
row_number() over(partition by t.rid order by t.time) rn
from mytable t
) t
group by date_trunc(day, t.time)
I think of this as two levels of aggregation. The inner one to get the earliest date. The outer to aggregate:
select first_day, count(*)
from (select rid, date_trunc('day', min(time))::date as first_day
from orders o
group by rid
) r
group by 1

Running count distinct

I am trying to see how the cumulative number of subscribers changed over time based on unique email addresses and date they were created. Below is an example of a table I am working with.
I am trying to turn it into the table below. Email 1#gmail.com was created twice and I would like to count it once. I cannot figure out how to generate the Running count distinct column.
Thanks for the help.
I would usually do this using row_number():
select date, count(*),
sum(count(*)) over (order by date),
sum(sum(case when seqnum = 1 then 1 else 0 end)) over (order by date)
from (select t.*,
row_number() over (partition by email order by date) as seqnum
from t
) t
group by date
order by date;
This is similar to the version using lag(). However, I get nervous using lag if the same email appears multiple times on the same date.
Getting the total count and cumulative count is straight forward. To get the cumulative distinct count, use lag to check if the email had a row with a previous date, and set the flag to 0 so it would be ignored during a running sum.
select distinct dt
,count(*) over(partition by dt) as day_total
,count(*) over(order by dt) as cumsum
,sum(flag) over(order by dt) as cumdist
from (select t.*
,case when lag(dt) over(partition by email order by dt) is not null then 0 else 1 end as flag
from tbl t
) t
DEMO HERE
Here is a solution that does not uses sum over, neither lag... And does produces the correct results.
Hence it could appear as simpler to read and to maintain.
select
t1.date_created,
(select count(*) from my_table where date_created = t1.date_created) emails_created,
(select count(*) from my_table where date_created <= t1.date_created) cumulative_sum,
(select count( distinct email) from my_table where date_created <= t1.date_created) running_count_distinct
from
(select distinct date_created from my_table) t1
order by 1

How to take only one entry from a table based on an offset to a date column value

I have a requirement to get values from a table based on an offset conditions on a date column.
Say for eg: for the below attached table, if there is any dates that comes close within 15 days based on effectivedate column I should return only the first one.
So my expected result would be as below:
Here for A1234 policy, it returns 6/18/16 entry and skipped 6/12/16 entry as the offset between these 2 dates is within 15 days and I took the latest one from the list.
If you want to group rows together that are within 15 days of each other, then you have a variant of the gaps-and-islands problem. I would recommend lag() and cumulative sum for this version:
select polno, min(effectivedate), max(expirationdate)
from (select t.*,
sum(case when prev_ed >= dateadd(day, -15, effectivedate)
then 1 else 0
end) over (partition by polno order by effectivedate) as grp
from (select t.*,
lag(expirationdate) over (partition by polno order by effectivedate) as prev_ed
from t
) t
) t
group by polno, grp;