Each time my user looks up a customer, I store the customer ID, Name and timestamp (timestamp = when the user performed the look up).
Kinda like:
ID Name Timestamp
1 CompanyA 2012-10-01 10:00
2 ComapnyB 2012-10-01 10:11
3 CompanyA 2012-10-01 10:22
4 CompanyA 2012-10-01 10:25
4 CompanyC 2012-10-01 10:32
My question is ...
I want to return TOP 30 distinct customers sorted by date descending - how do I do that?
I want to return this:
CompanyC
CompanyA
CompanyB
... only a single instance sorted by the date descending.
SELECT TOP 30 Name
FROM Customer
GROUP BY Name
ORDER BY MAX(Timestamp) DESC
Related
This question already has answers here:
Is there a way to access the "previous row" value in a SELECT statement?
(9 answers)
Closed 7 months ago.
I have a table in SQL Server with sales price data of items on different dates like this:
Item
Date
Price
1
2021-05-01
200
1
2021-06-11
210
1
2021-06-27
225
1
2021-08-01
250
2
2021-02-10
600
2
2021-04-21
650
2
2021-06-17
675
2
2021-07-23
700
I'm creating a table that specifies the start and end date of prices as below:
Item
DateStart
Price
DateEnd
1
2021-05-01
200
2021-06-10
1
2021-06-11
210
2021-06-26
1
2021-06-27
225
2021-07-31
1
2021-08-01
250
Today date
2
2021-02-10
600
2021-04-20
2
2021-04-21
650
2021-06-16
2
2021-06-17
675
2021-07-22
2
2021-07-23
700
Today date
As you can see, the end date is one day less than the next price change date. I also have a calendar table called "DimDates" with one row per day. I had hoped to use joins but it doesn't do what I thought it would do. Any suggestions on how to write the query? I'm using SQL Server 2016.
We can use LEAD() here along with DATEADD():
WITH cte AS (
SELECT *, DATEADD(day, -1, LEAD(Date, 1, GETDATE())
OVER (PARTITION BY Item
ORDER BY Date)) AS LastDate
FROM yourTable
)
SELECT Item, Date AS DateStart, Price, LastDate AS DateEnd
FROM cte
ORDER BY Item, Date;
Demo
In the project I am currently working on in my company, I would like to show sales related KPIs together with Customer Score metric on SQL / Tableau / BigQuery
The primary key is order id in both tables. However, order date and the date we measure Customer Score may be different. For example the the sales information for an order that is released in Feb 2020 will be aggregated in Feb 2020, however if the customer survey is made in March 2020, the Customer Score metric must be aggregated in March 2020. And what I would like to achieve in the relational database is as follows:
Sales:
Order ID
Order Date(m/d/yyyy)
Sales ($)
1000
1/1/2021
1000
1001
2/1/2021
2000
1002
3/1/2021
1500
1003
4/1/2021
1700
1004
5/1/2021
1800
1005
6/1/2021
900
1006
7/1/2021
1600
1007
8/1/2021
1900
Customer Score Table:
Order ID
Customer Survey Date(m/d/yyyy)
Customer Score
1000
3/1/2021
8
1001
3/1/2021
7
1002
4/1/2021
3
1003
6/1/2021
6
1004
6/1/2021
5
1005
7/1/2021
3
1006
9/1/2021
1
1007
8/1/2021
7
Expected Output:
KPI
Jan-21
Feb-21
Mar-21
Apr-21
May-21
June-21
July-21
Aug-21
Sep-21
Sales($)
1000
2000
1500
1700
1800
900
1600
1900
AVG Customer Score
7.5
3
5.5
3
7
1
I couldn't find a way to do this, because order date and survey date may/may not be the same.
For sample data and expected output, click here.
I think what you want to do is aggregate your results to the month (KPI) first before joining, as opposed to joining on the ORDER_ID
For example:
with order_month as (
select date_trunc(order_date, MONTH) as KPI, sum(sales) as sales
from `testing.sales`
group by 1
),
customer_score_month as (
select date_trunc(customer_survey_date, MONTH) as KPI, avg(customer_score) as avg_customer_score
from `testing.customer_score`
group by 1
)
select coalesce(order_month.KPI,customer_score_month.KPI) as KPI, sales, avg_customer_score
from order_month
full outer join customer_score_month
on order_month.KPI = customer_score_month.KPI
order by 1 asc
Here, we aggregate the total sales for each month based on the order date, then we aggregate the average customer score for each month based on the date the score was submitted. Now we can join these two on the month value.
This results in a table like this:
KPI
sales
avg_customer_score
2021-01-01
1000
null
2021-02-01
2000
null
2021-03-01
1500
7.5
2021-04-01
1700
3.0
2021-05-01
1800
null
2021-06-01
900
5.5
2021-07-01
1600
3.0
2021-08-01
1900
7.0
2021-09-01
null
1.0
You can pivot the results of this table in Tableau, or leverage a case statement to pull out each month into its own column - I can elaborate more if that will be helpful
Wondering how to select from a table:
FIELDID personID purchaseID dateofPurchase
--------------------------------------------------
2 13 147 2014-03-21 00:00:00
3 15 165 2015-03-23 00:00:00
4 13 456 2018-03-24 00:00:00
5 1 133 2018-03-21 00:00:00
6 23 123 2013-03-22 00:00:00
7 25 456 2013-03-21 00:00:00
8 25 456 2013-03-23 00:00:00
9 22 456 2013-03-28 00:00:00
10 25 589 2013-03-21 00:00:00
11 82 147 1991-10-22 00:00:00
12 82 453 2003-03-22 00:00:00
I'd like to get a result table of two columns: weekday and the number of purchases of each weekday, but only count the distinct days of purchases if done by the same person on the same day - for example since personID 25 purchased two things on 2013-03-21, that should only count as one 'thursday' instead of 2.
Basically, if the personID and the dateofPurchase are the same for more than one row, only count it once is what I want.
Here is what I have currently: It does everything correctly except it will count the above scenario under the thursday twice, when I would only want to add one:
SELECT v.wkday as day, COUNT(*) as 'absences'
FROM dbo.AttendanceRecord pr CROSS APPLY
(VALUES (CASE WHEN DATEPART(WEEKDAY, date) IN (1, 7)
THEN 'Weekend'
ELSE DATENAME(WEEKDAY, date)
END)
) v(wkday)
GROUP BY v.wkday;
to clarify:
If an item is purchased for at least one puchaseID on a specific day they will be counted as purchased for that day, and do not need to be counted again for each new purchase ID on that day.
I think you want to count distinct persons, so that would be:
COUNT(DISTINCT personid) as absences
Note that single quotes are not appropriate around column aliases. If you need to escape them, use square braces.
EDIT:
If you want to count distinct person-days, then you can use:
COUNT(DISTINCT CONCAT(personid, ':', dateofpurchase) as absences
I am dealing with the following problem in SQL (using Vertica):
In short -- Create a timeline for each ID (in a table where I have multiple lines, orders in my example, per ID)
What I would like to achieve -- At my disposal I have a table on historical order date and I would like to compute new customer (first order ever in the past month), active customer- (>1 order in last 1-3 months), passive customer- (no order for last 3-6 months) and inactive customer (no order for >6 months) rates.
Which steps I have taken so far -- I was able to construct a table similar to the example presented below:
CustomerID Current order date Time between current/previous order First order date (all-time)
001 2015-04-30 12:06:58 (null) 2015-04-30 12:06:58
001 2015-09-24 17:30:59 147 05:24:01 2015-04-30 12:06:58
001 2016-02-11 13:21:10 139 19:50:11 2015-04-30 12:06:58
002 2015-10-21 10:38:29 (null) 2015-10-21 10:38:29
003 2015-05-22 12:13:01 (null) 2015-05-22 12:13:01
003 2015-07-09 01:04:51 47 12:51:50 2015-05-22 12:13:01
003 2015-10-23 00:23:48 105 23:18:57 2015-05-22 12:13:01
A little bit of intuition: customer 001 placed three orders from which the second one was 147 days after its first order. Customer 002 has only placed one order in total.
What I think that the next steps should be -- I would like to know for each date (also dates on which a certain user did not place an order), for each CustomerID, how long it has been since his/her last order. This would imply that I would create some sort of timeline for each CustomerID. In the example presented above I would get 287 (days between 1st of May 2015 and 11th of February 2016, the timespan of this table) lines for each CustomerID. I have difficulties solving this previous step. When I have performed this step I want to create a field which shows at each date the last order date, the period between the last order date and the current date, and what state someone is in at the current date. For the example presented earlier, this would look something like this:
CustomerID Last order date Current date Time between current date /last order State
001 2015-04-30 12:06:58 2015-05-01 00:00:00 0 00:00:00 New
...
001 2015-04-30 12:06:58 2015-06-30 00:00:00 60 11:53:02 Active
...
001 2015-09-24 17:30:59 2016-02-01 00:00:00 129 11:53:02 Passive
...
...
002 2015-10-21 17:30:59 2015-10-22 00:00:00 0 06:29:01 New
...
002 2015-10-21 17:30:59 2015-11-30 00:00:00 39 06:29:01 Active
...
...
003 2015-05-22 12:13:01 2015-06-23 00:00:00 31 11:46:59 Active
...
003 2015-07-09 01:04:51 2015-10-22 00:00:00 105 11:46:59 Inactive
...
At the dots there should be all the inbetween dates but for sake of space I have left these out of the table.
When I know for each date what the state is of each customer (active/passive/inactive) my plan is to sum the states and group by date which should give me the sum of new, active, passive and inactive customers. From here on I can easily compute the rates at each date.
Anybody that knows how I can possibly achieve this task?
Note -- If anyone has other ideas how to achieve the goal presented above (using some other approach compared to the approach I had in mind) please let me know!
EDIT
Suppose you start from a table like this:
SQL> select * from ord order by custid, ord_date ;
custid | ord_date
--------+---------------------
1 | 2015-04-30 12:06:58
1 | 2015-09-24 17:30:59
1 | 2016-02-11 13:21:10
2 | 2015-10-21 10:38:29
3 | 2015-05-22 12:13:01
3 | 2015-07-09 01:04:51
3 | 2015-10-23 00:23:48
(7 rows)
You can use Vertica's Timeseries Analytic Functions TS_FIRST_VALUE(), TS_LAST_VALUE() to fill gaps and interpolate last_order date to the current date:
Then you just have to join this with a Vertica's TimeSeries generated from the same table with interval one day starting from the first day each customer did place his/her first order up to now (current_date):
select
custid,
status_dt,
last_order_dt,
case
when status_dt::date - last_order_dt::date < 30 then case
when nord = 1 then 'New' else 'Active' end
when status_dt::date - last_order_dt::date < 90 then 'Active'
when status_dt::date - last_order_dt::date < 180 then 'Passive'
else 'Inactive'
end as status
from (
select
custid,
last_order_dt,
status_dt,
conditional_true_event (first_order_dt is null or
last_order_dt > lag(last_order_dt))
over(partition by custid order by status_dt) as nord
from (
select
custid,
ts_first_value(ord_date) as first_order_dt ,
ts_last_value(ord_date) as last_order_dt ,
dt::date as status_dt
from
( select custid, ord_date from ord
union all
select distinct(custid) as custid, current_date + 1 as ord_date from ord
) z timeseries dt as '1 day' over (partition by custid order by ord_date)
) x
) y
where status_dt <= current_date
order by 1, 2
;
And you will get something like this:
custid | status_dt | last_order_dt | status
--------+------------+---------------------+---------
1 | 2015-04-30 | 2015-04-30 12:06:58 | New
1 | 2015-05-01 | 2015-04-30 12:06:58 | New
1 | 2015-05-02 | 2015-04-30 12:06:58 | New
...
1 | 2015-05-29 | 2015-04-30 12:06:58 | New
1 | 2015-05-30 | 2015-04-30 12:06:58 | Active
1 | 2015-05-31 | 2015-04-30 12:06:58 | Active
...
etc.
I wanted to do something like this post, so I tried:
SELECT
ROW_NUMBER() OVER(ORDER BY t.[Data Saida] ) AS id,
t.codigo, t.[Data Saida], t.Entidade, t.DataEnt,
t.[GTEntT Nº], t.Estado, t.[GTSaida Nº], t.[Observações1],
t.Eequisitante, t.Certificado, T.Resultado, T.Seleccionar, t.[Tipo de Intervenção]
FROM
[Movimento ferramentas] t;
However I ended up getting something like
Syntax error (missing operator) in query expression ROW_NUMBER() OVER(ORDER BY t.[Data Saida] )
Is it because ROW_NUMBER() OVER() is SQL Server only or am I doing something wrong?
I'm working with MS Access 2010.
Here's a row from that table:
To add an AutoNumber field to an existing table, simply open the table in Design View, type in the Field Name and select "AutoNumber" from the drop-down list for the Data Type:
Access will populate the new field with AutoNumber values for any existing records in the table.
Edit re: influencing the order in which AutoNumber values are applied to existing records
As with many other database operations, there is essentially no guarantee that Access will use any particular order when assigning the AutoNumber values to existing records. However, if we look at a couple of examples we can see how Access will likely do it.
Consider the following sample table named [Events]. The rows were entered in random order and there is no primary key:
EventDate Event
---------- --------------
2012-06-01 it's June
2012-10-01 it's October
2012-09-01 it's September
2012-12-01 it's December
2012-11-01 it's November
2012-07-01 it's July
2012-04-01 it's April
2012-08-01 it's August
2012-02-01 it's February
2012-01-01 it's January
2012-03-01 it's March
2012-05-01 it's May
Now we'll simply add an AutoNumber field named [ID] using the procedure above. After that has been done
SELECT * FROM Events ORDER BY ID
returns
EventDate Event ID
---------- -------------- --
2012-06-01 it's June 1
2012-10-01 it's October 2
2012-09-01 it's September 3
2012-12-01 it's December 4
2012-11-01 it's November 5
2012-07-01 it's July 6
2012-04-01 it's April 7
2012-08-01 it's August 8
2012-02-01 it's February 9
2012-01-01 it's January 10
2012-03-01 it's March 11
2012-05-01 it's May 12
Now let's revert back to the old copy of the table and see if the existence of a primary key makes a difference. We'll make [Event Date] the primary key, save the changes to the table, and then add the [ID] AutoNumber field. After that is done, the select statement above gives us
EventDate Event ID
---------- -------------- --
2012-06-01 it's June 1
2012-10-01 it's October 2
2012-09-01 it's September 3
2012-12-01 it's December 4
2012-11-01 it's November 5
2012-07-01 it's July 6
2012-04-01 it's April 7
2012-08-01 it's August 8
2012-02-01 it's February 9
2012-01-01 it's January 10
2012-03-01 it's March 11
2012-05-01 it's May 12
Hmmm, same thing. So it looks like the AutoNumber values get assigned to the table in natural order (the order in which the records were added to the table) even if there is a primary key.
Okay, if that's the case then let's use a make-table query to create a new copy of the table in a different order
SELECT Events.EventDate, Events.Event
INTO Events2
FROM Events
ORDER BY Events.EventDate;
Now let's add the [ID] AutoNumber field to that new table and see what we get:
SELECT * FROM Events2 ORDER BY ID
returns
EventDate Event ID
---------- -------------- --
2012-01-01 it's January 1
2012-02-01 it's February 2
2012-03-01 it's March 3
2012-04-01 it's April 4
2012-05-01 it's May 5
2012-06-01 it's June 6
2012-07-01 it's July 7
2012-08-01 it's August 8
2012-09-01 it's September 9
2012-10-01 it's October 10
2012-11-01 it's November 11
2012-12-01 it's December 12
If that is the order we want then we can just delete the [Events] table and rename [Events2] to [Events].