I have a Postgresql database, and I'm having trouble getting my query right, even though this seems like a common problem.
My table looks like this:
CREATE TABLE orders (
account_id INTEGER,
order_id INTEGER,
ts TIMESTAMP DEFAULT NOW()
)
Everytime there is a new order, I use it to link the account_id and order_id.
Now my problem is that I want to get a list that has the last order (by looking at ts) for each account.
For example, if my data is:
account_id order_id ts
5 178 July 1
5 129 July 6
4 190 July 1
4 181 July 9
3 348 July 1
3 578 July 4
3 198 July 1
3 270 July 12
Then I'd like the query to return only the last row for each account:
account_id order_id ts
5 129 July 6
4 181 July 9
3 270 July 12
I've tried GROUP BY account_id, and I can use that to get the MAX(ts) for each account, but then I have no way to get the associated order_id. I've also tried sub-queries, but I just can't seem to get it right.
Thanks!
select distinct on (account_id) *
from orders
order by account_id, ts desc
https://www.postgresql.org/docs/current/static/sql-select.html#SQL-DISTINCT:
SELECT DISTINCT ON ( expression [, ...] ) keeps only the first row of each set of rows where the given expressions evaluate to equal. The DISTINCT ON expressions are interpreted using the same rules as for ORDER BY (see above). Note that the "first row" of each set is unpredictable unless ORDER BY is used to ensure that the desired row appears first.
The row_number() window function can help:
select account_id, order_id, ts
from (select account_id, order_id, ts,
row_number() over(partition by account_id order by ts desc) as rn
from tbl) t
where rn = 1
Related
My table is currently looking like this:
+---------+---------------+------------+------------------+
| Segment | Product | Pre_Date | ON_Prepaid |
+---------+---------------+------------+------------------+
| RB | 01. Auto Loan | 2020-01-01 | 10645976180.0000 |
| RB | 01. Auto Loan | 2020-01-02 | 4489547174.0000 |
| RB | 01. Auto Loan | 2020-01-03 | 1853117000.0000 |
| RB | 01. Auto Loan | 2020-01-04 | 9350258448.0000 |
+---------+---------------+------------+------------------+
I'm trying to sum values of 'ON_Prepaid' over the course of 7 days, let's say from '2020-01-01' to '2020-01-07'.
Here is what I've tried
drop table if exists ##Prepay_summary_cash
select *,
[1W_Prepaid] = sum(ON_Prepaid) over (partition by SEGMENT, PRODUCT order by PRE_DATE rows between 1 following and 7 following),
[2W_Prepaid] = sum(ON_Prepaid) over (partition by SEGMENT, PRODUCT order by PRE_DATE rows between 8 following and 14 following),
[3W_Prepaid] = sum(ON_Prepaid) over (partition by SEGMENT, PRODUCT order by PRE_DATE rows between 15 following and 21 following),
[1M_Prepaid] = sum(ON_Prepaid) over (partition by SEGMENT, PRODUCT order by PRE_DATE rows between 22 following and 30 following),
[1.5M_Prepaid] = sum(ON_Prepaid) over (partition by SEGMENT, PRODUCT order by PRE_DATE rows between 31 following and 45 following),
[2M_Prepaid] = sum(ON_Prepaid) over (partition by SEGMENT, PRODUCT order by PRE_DATE rows between 46 following and 60 following),
[3M_Prepaid] = sum(ON_Prepaid) over (partition by SEGMENT, PRODUCT order by PRE_DATE rows between 61 following and 90 following),
[6M_Prepaid] = sum(ON_Prepaid) over (partition by SEGMENT, PRODUCT order by PRE_DATE rows between 91 following and 181 following)
into ##Prepay_summary_cash
from ##Prepay1
Things should be fine if the dates are continuous; however, there are some missing days in 'Pre_Date' (you know banks don't work on Sundays, etc.).
So I'm trying to work on something like
[1W] = SUM(ON_Prepaid) over (where Pre_date between dateadd(d,1,Pre_date) and dateadd(d,7,Pre_date))
something like that. So if per se there's no record on 2020-01-05, the result should only sum the dates on the 1,2,3,4,6,7 of Jan 2020, instead of 1,2,3,4,6,7,8 (8 because of "rows 7 following"). Or for example I have missing records over the span of 30 days or something, then all those 30 should be summed as 0s. So 45 days should return only the value of 15 days.
I've tried looking up all over the forum and the answers did not suffice. Can you guys please help me out? Or link me to a thread which the problem had already been solved.
Thank you so much.
Things should be fine if the dates are continuous
Then make them continuous. Left join your real data (grouped up so it is one row per day) onto your calendar table (make one, or use a recursive cte to generate you a list of 360 dates from X hence) and your query will work out
WITH d as
(
SELECT *
FROM
(
SELECT *
FROM cal
CROSS JOIN
(SELECT DISTINCT segment s, product p FROM ##Prepay1) x
) c
LEFT JOIN ##Prepay1 p
ON
c.d = p.pre_date AND
c.segment = p.segment AND
c.product = p.product
WHERE
c.d BETWEEN '2020-01-01' AND '2021-01-01' -- date range on c.d not c.pre_date
)
--use d.d/s/p not d.pre_date/segment/product in your query (sometimes the latter are null)
select *,
[1W_Prepaid] = sum(ON_Prepaid) over (partition by s, s order by d.d rows between 1 following and 7 following),
...
CAL is just a table with a single column of dates, one per day, no time, extending for n thousand days into the past/future
Wish to note that months have variable number of days so 6M is a bit of a misnomer.. might be better to call the month ones 180D, 90D etc
Also want to point out that your query performs a per row division of your data into into groups. If you want to perform sums up to 180 days after the date of the row you need to pull a year's worth of data so that on row 180(June) you have the December data available to sum (dec being 6 months from June)
If you then want to restrict your query to only showing up to June (but including data summed from 6 months after June) you need to wrap it all again in a sub query. You cannot "where between jan and jun" in the query that does the sum over because where clauses are done before window clauses (doing so will remove the dec data before it is summed)
Some other databases make this easier, Oracle and Postgres spring to mind; they can perform sum in a range where the other rows values are within some distance of the current row's values. SQL server only usefully supports distancing based on a row's index rather than its values (the distancing-based-on-values support is limited to "rows that have the same value", rather than "rows that have values n higher or lower than the current row"). I suppose the requirement could be met with a cross apply, or a coordinated sub in the select, though I'd be careful to check the performance..
SELECT *,
(SELECT SUM(tt.a) FROM x tt WHERE t.x = tt.x AND tt.y = t.y AND tt.z BETWEEN DATEADD(d, 1, t.z) AND DATEADD(d, 7, t.z) AS 1W
FROM
x t
I'm trying to get a running total within a group but my current code just gives me an aggregate sum.
For example, my data looks like this
ID ShiftNum Status Type Rate HourlyWage Hours Total_Amount
12542 1 Full A 1 12.5 40 500
12542 1 Full A 1 12.5 35 420
12542 2 Full A 1 10 40 400
12542 2 Full B 1.2 10 40 480
17842 1 Full A 1 11 27 297
17842 1 Full B 1.3 11 30 429
And what I want is a running total within the same ID, Shift Number, and Status. For example, I want something like this as my final result
ID ShiftNum Status Type Rate HourlyWage Hours Total_Amount Running_Tot
12542 1 Full A 1 12.5 40 500 500
12542 1 Full A 1 12.5 35 420 920
12542 2 Full A 1 10 40 400 400
12542 2 Full B 1.2 10 40 480 880
17842 1 Full A 1 11 27 297 297
17842 1 Full B 1.3 11 30 429 726
However, my current code just gives me the total sum within each group. For example, 920, 920 for row 1&2. Here's my code.
Select a.*,
SUM(Hours) OVER (PARTITION BY ID, ShiftNum, Status ORDER BY ID, ShiftNum, Status) as Runnint_Tot
from table a
How do I fix my code to get the final result I want?
You need an ordering column that uniquely defines each row. There is not an obvious one in your row, but something like this:
SUM(Hours) OVER (PARTITION BY ID, ShiftNum, Status ORDER BY hours) as Running_Tot
Or:
SUM(Hours) OVER (PARTITION BY ID, ShiftNum, Status
ORDER BY (SELECT NULL)
ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
) as Running_Tot
The problem you are facing is because the ORDER BY keys have ties. The default window frame is RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW. Note the RANGE. That means that all rows with ties are combined.
Also note that there is no utility to including the PARTITION BY keys in the ORDER BY (well . . . there is one exception in SQL Server if you don't care about the ordering, then including a key can be a handy short-cut). The ordering occurs within a partition.
If your rows can have exact duplicates, I would first suggest that you add a primary key. But, in the meantime, you could use:
with a as (
select a.*,
row_number() over (order by id, shiftnum, status) as seqnum
from tablea a
)
Select a.*,
SUM(Hours) OVER (PARTITION BY ID, ShiftNum, Status ORDER BY seqnum) as Running_Tot
from a;
The ordering will be arbitrary, but it will at least accumulate.
Following on from a previous question, in which i have a table called orders with information regarding the time an order was placed and who made that order.
order_timestamp user_id
-------------------- ---------
1-JUN-20 02.56.12 123
3-JUN-20 12.01.01 533
23-JUN-20 08.42.18 123
12-JUN-20 02.53.59 238
19-JUN-20 02.33.72 34
I would like to calculate a daily rolling count of the number of days a user made an order in a past 10 days.
For example, in the last 10 days from the 20th June, user 34 made an order on 5 of those days. Then in the last 10 days from the 21st June, user 34 made an order on 6 of those days
In the end the table should be like this:
date user_id no_of_days
----------- --------- ------------
20-JUN-20 34 5
20-JUN-20 123 10
20-JUN-20 533 2
20-JUN-20 238 3
21-JUN-20 34 6
21-JUN-20 123 10
How would the query be written for this kind of analysis?
Please let me know if my question is unclear/more infor is required.
Thanks to you in advancement.
You can use window functions for this. Start by getting one row per user per day. And then use a rolling sum:
select day, user_id,
count(*) over (partition by user_id range between interval '10' day preceding and current row)
from (select distinct trunc(order_timestamp) as day, user_id
from t
) t
Assuming that a user places one order a day maximum, you can use window functions as follows:
select
t.*,
count(*) over(partition by user_id order by trunc(order_timestamp) range 10 preceding) no_of_days
from mytable t
Otherwise, you can get the distinct orders per day first:
select
order_day,
user_id,
count(*) over(partition by user_id order by order_day range 10 preceding) no_of_days
from (select distinct trunc(order_timestamp) order_day, user_id from mytable) t
I have a table that looks like the following
id effective_date number_of_int_customers
123 10/01/19 0
123 02/01/20 3
456 10/01/19 6
456 02/01/20 6
789 10/01/19 5
789 02/01/20 4
999 10/01/19 0
999 02/01/20 1
I want to write a query that looks at each ID to see if the salespeople have newly started working internationally between October 1st and February 1st.
The result I am looking for is the following:
id effective_date number_of_int_customers
123 02/01/20 3
999 02/01/20 1
The result would return only the salespeople who originally had 0 international customers and now have at least 1.
I have seen similar posts here that use nested queries to pull records where the first date and last have different values. But I only want to pull records where the original value was 0. Is there a way to do this in one query in SQL?
In your case, a simple aggregation would do -- assuming that 0 is the earliest value:
select id, max(number_of_int_customers)
from t
where effective_date in ('2019-10-01', '2020-02-01')
group by id
having min(number_of_int_customers) = 0;
Obviously, this is not correct if the values can decrease to zero. But this having clause fixes that problem:
having min(case when number_of_int_customers = 0 then effective_date end) = min(effective_date)
An alternative is to use window functions, such asfirst_value():
select distinct id, last_noic
from (select t.*,
first_value(number_of_int_customers) over (partition by id order by effective_date) as first_noic,
first_value(number_of_int_customers) over (partition by id order by effective_date desc) as last_noic,
from t
where effective_date in ('2019-10-01', '2020-02-01')
) t
where first_noic = 0;
Hmmm, on second thought, I like lag() better:
select id, number_of_int_customers
from (select t.*,
lag(number_of_int_customers) over (partition by id order by effective_date) as prev_noic
from t
where effective_date in ('2019-10-01', '2020-02-01')
) t
where prev_noic = 0;
In a firebird database with a table "Sales", I need to select the first sale of all customers. See below a sample that show the table and desired result of query.
---------------------------------------
SALES
---------------------------------------
ID CUSTOMERID DTHRSALE
1 25 01/04/16 09:32
2 30 02/04/16 11:22
3 25 05/04/16 08:10
4 31 07/03/16 10:22
5 22 01/02/16 12:30
6 22 10/01/16 08:45
Result: only first sale, based on sale date.
ID CUSTOMERID DTHRSALE
1 25 01/04/16 09:32
2 30 02/04/16 11:22
4 31 07/03/16 10:22
6 22 10/01/16 08:45
I've already tested following code "Select first row in each GROUP BY group?", but it did not work.
In Firebird 2.5 you can do this with the following query; this is a minor modification of the second part of the accepted answer of the question you linked to tailored to your schema and requirements:
select x.id,
x.customerid,
x.dthrsale
from sales x
join (select customerid,
min(dthrsale) as first_sale
from sales
group by customerid) p on p.customerid = x.customerid
and p.first_sale = x.dthrsale
order by x.id
The order by is not necessary, I just added it to make it give the order as shown in your question.
With Firebird 3 you can use the window function ROW_NUMBER which is also described in the linked answer. The linked answer incorrectly said the first solution would work on Firebird 2.1 and higher. I have now edited it.
Search for the sales with no earlier sales:
SELECT S1.*
FROM SALES S1
LEFT JOIN SALES S2 ON S2.CUSTOMERID = S1.CUSTOMERID AND S2.DTHRSALE < S1.DTHRSALE
WHERE S2.ID IS NULL
Define an index over (customerid, dthrsale) to make it fast.
in Firebird 3 , get first row foreach customer by min sales_date :
SELECT id, customer_id, total, sales_date
FROM (
SELECT id, customer_id, total, sales_date
, row_number() OVER(PARTITION BY customer_id ORDER BY sales_date ASC ) AS rn
FROM SALES
) sub
WHERE rn = 1;
İf you want to get other related columns, This is where your self-answer fails.
select customer_id , min(sales_date)
, id, total --what about other colums
from SALES
group by customer_id
So simple as:
select CUSTOMERID min(DTHRSALE) from SALES group by CUSTOMERID