finding the number of days in between first 2 date point - sql

So the question seems to be quite difficult I wonder if I could get some advice from here. I am trying to solve this with SQLite 3. So I have a data format of this.
customer | purchase date
1 | date 1
1 | date 2
1 | date 3
2 | date 4
2 | date 5
2 | date 6
2 | date 7
number of times the customer repeats is random.
so I just want to find whether customer 1's 1st and 2nd purchase date are fallen in between a specific time period. repeat for other customers. only need to consider 1st and 2nd dates.
Any help would be appreciated!

We can try using ROW_NUMBER here:
WITH cte AS (
SELECT *, ROW_NUMBER() OVER (PARTITION BY customer ORDER BY "purchase date") rn
FROM yourTable
)
SELECT
customer,
CAST(MAX(CASE WHEN rn = 2 THEN julianday("purchase date") END) -
MAX(CASE WHEN rn = 1 THEN julianday("purchase date") END) AS INTEGER) AS diff_in_days
FROM cte
GROUP BY
customer;
The idea here is to aggregate by customer and then take the date difference between the second and first purchase. ROW_NUMBER is used to find these first and second purchases, for each customer.

Related

Find Individuals who have purchased 10 times within a rolling 1 year period

So let's say I have 2 tables. One table is for consumers, and another is for sales.
Consumers
ID
Name
...
1
John Johns
...
2
Cathy Dans
...
Sales
ID
consumer_id
purchase_date
...
1
1
01/03/05
...
2
1
02/04/10
...
3
1
03/04/11
...
4
2
02/14/07
...
5
2
09/24/08
...
6
2
12/15/09
...
I want to find all instances of consumers who made more than 10 purchases within any 6 month rolling period.
SELECT
consumers.id
, COUNT(sales.id)
FROM
consumers
JOIN sales ON consumers.id = sales.consumer_id
GROUP BY
consumers.id
HAVING
COUNT(sales.id) >= 10
ORDER BY
COUNT(sales.id) DESC
So I have this code, which just gives me a list of consumers who have made more than 10 purchases ALL TIME. But how do I incorporate the rolling 6 month period logic?!
Any help or guidance on which functions can help me accomplish this would be appreciated!
You can use window functions to count the number of sales in a six-month period. Then just filter down to those consumers:
select distinct consumer_id
from (select s.*,
count(*) over (partition by consumer_id
order by purchase_date
range between current row and interval '6 month' following
) as six_month_count
from sales s
) s
where six_month_count > 10;

SQL Troubleshooting Help on Table Structure

I'm attempting to calculate average number of days between a customer's 1st and 3rd purchase, but struggling to get the data ordered in a way that will allow me to calculate.
I currently have the below data table. (Note: Order sequence number refers to the number order for that customer.)
Order Date
Customer Number
Order Sequence Number
2020-09-20
1
1
2021-01-20
1
2
2021-01-21
1
3
2020-10-01
2
1
2020-08-06
3
1
2020-09-06
3
2
2020-09-09
3
3
I've been trying to get the data to look like the following table. [To then be able to calculate datediff on the last two columns.]
Customer Number
Order Count
First Order Date
Third Order Date
1
3
2020-09-20
2021-01-21
2
1
2020-10-01
Null
3
3
2020-08-06
2020-09-09
I've completely messed up the code, but here's what I've been trying.
CREATE TABLE X2 as
SELECT
customer_number,
max(order_sequence_number) as order_count,
CASE
WHEN order_sequence_number = 1 then order_date
ELSE null
END as first_order_date,
CASE
WHEN order_sequence_number = 3 then order_date
ELSE null
END as third_order_date
FROM X1
GROUP BY customer_number;
Can someone please tell me what I'm missing? Thanks in advance!
You are on the right track but you need aggregation functions:
SELECT customer_number,
max(order_sequence_number) as order_count,
MAX(CASE WHEN order_sequence_number = 1 THEN order_date END) as first_order_date,
MAX(CASE WHEN order_sequence_number = 3 THEN order_date END) as third_order_date
FROM X1
GROUP BY customer_number;
To get the difference in days, you would just subtract the two expressions using whatever date arithmetic is supported in your database.

Apply SUM( where date between date1 and date2)

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

SQL : How to count number of times each ID exists continuously from previous period

My SQL data set is like this;
Date firm_id
======================
2010-01 1
2010-01 2
2010-01 3
----------------------
2010-02 1
2010-02 2
----------------------
2010-03 1
2010-03 2
2010-03 3
----------------------
2010-04 1
2010-04 3
How can I create a variable, name firm_age, to represent age of firms existing continuously from the previous period? like this,
Date firm_id firm_age
=================================
2010-01 1 0
2010-01 2 0
2010-01 3 0
-----------------------------------
2010-02 1 1
2010-02 2 1
-----------------------------------
2010-03 1 2
2010-03 2 2
2010-03 3 0
-----------------------------------
2010-04 1 3
2010-04 3 1
Thank you
This is a use case for the PACK operator from "Time & Relational Theory", which is not supported, at least not directly, in SQL.
You are trying to find [for each given row of the table] the smallest month such that there does not exist any intervening month between that smallest month and the month of the given row such that the company of the given row did not exist at that intervening month. Given two months, assessing the [non-]existence of such an intervening month is relatively trivial, however, finding the smallest month that makes the condition true for all intervening months is another order (*). I wouldn't try to do this completely in plain SQL.
(*) which set of months are you going to SELECT that "smallest month" from ? You cannot rely on the fact that all months will be mentioned in your table as there is always the slight theoretical possibility that one particular month, no companies existed at all. (This possibility also breaks any attack on the problem based on window functions ans row_numbers.)
This is a gaps-and-islands problem. You want "islands" where the values are sequential. Then you want to enumerate them. You can use row_number() for this:
select t.*,
row_number() over (partition by firm_id, date - seqnum * interval '1 month'
order by date
) as firm_age
from (select t.*,
row_number() over (partition by firm_id order by date) as seqnum
from t
) t;
Note that date functions are not standard across databases. This makes some assumptions about the data representation, but the idea for the processing should work in almost any database.

Find how many times it took to achieve a particular outcome in SQL Table

I need to find out how many attempts it takes to achieve an outcome from a SQL table. For example My table contains CustomerID, Outcome, OutcomeType. The outcome I am looking for is Sale
So if I had this record:
CID Outcome OutcomeID Date
1 No Answer 0 01/01/2015 08:00:00
1 No Interest 0 02/01/2015 09:00:00
1 Sale 1 02/02/2015 10:00:00
1 Follow up 2 03/02/2015 10:00:00
I can see it took 2 attempts to get a sale. I need to do this for all the customers in a table which contains thousands of entries. They may have entries after the sale and I need to exclude these, they may also have additional sales after the first but I am only interested in the first sale.
i hope this is enough info,
many thanks in advance
Edit as requested, the outcome I would look for would be:
CID CountToOutcome
1 2
2 3
3 5
etc
You can do this with window functions and aggregation:
select cid,
min(case when Outcome = 'Sale' then seqnum end) - 1 as AttemptsBeforeSale
from (select t.*,
row_number() over (partition by cid order by date) as seqnum
from t
) t
group by cid;
Note: This provides the value for the first sale for each cid.