The question is:
List all of customer id that had their FIRST 3 GOJEK orders EXACTLY IN THE following sequence: First order is RIDE, second is CAR and third is FOOD
and the preview of table is:
I'm considering doing things like get the customers whose first order is RIDE, customers whose second order is CAR and customers whose thrid order is FOOD separately, and then intersect among them. But I ran out of ideas for querying on the second and third order type.
Thanks in advance!
You would do:
select d.customer_no
from daily_order d
group by d.customer_no
having to_json_string(array_agg(order_type order by order_time limit 3)) = to_json_string(array['RIDE', 'CAR', 'FOOD']);
Related
I have a table which has ID, FAMILY, ENV_XML_PATH and CREATED_DATE columns.
ID
FAMILY
ENV_XML_PATH
CREATED_DATE
15826841
CRM
path1.xml
03-09-22 6:50:34AM
15826856
SCM
path3.xml
03-10-22 7:12:20AM
15826786
IC
path4.xml
02-10-22 12:50:52AM
15825965
CRM
path5.xml
02-10-22 1:50:52AM
15653951
null
path6.xml
04-10-22 12:50:52AM
15826840
FIN
path7.xml
03-10-22 2:34:09AM
15826841
SCM
path8.xml
02-10-22 8:40:52AM
15223450
IC
path9.xml
03-09-22 5:34:09AM
15026853
SCM
path10.xml
05-10-22 4:40:59AM
Now there are 18 DISTINCT values in FAMILY column and each value has multiple rows associated (as you can see from the above image).
What I want is to get the first row of 3 specific values (CRM, SCM and IC) in FAMILY column.
Something like this:
ID
FAMILY
ENV_XML_PATH
CREATED_DATE
15826841
CRM
path1.xml
date1
15826856
SCM
path3.xml
date2
15826786
IC
path4.xml
date3
I am new to this, though I understand the logic but I am not sure how to implement it. Kindly help. Thanks.
You can use RANK for that. Something like this:
WITH groupedData AS
(SELECT id, family, env_xml_path, created_date,
RANK () OVER (PARTITION BY family ORDER BY id) AS r_num
FROM yourtable
GROUP BY id, family, env_xml_path, created_date)
SELECT id, family, env_xml_path, created_date
FROM groupedData
WHERE r_num = 1
ORDER BY id;
Thus, within the first query, your data will be grouped by family and sorted by the column you want (in my example, it will be sorted by id).
After that, you will use the second query to only take the first row of each family.
Add a WHERE clause to the first query if you need to apply further restrictions on the result set.
See here a working example: db<>fiddle
You could use a window function to get to know the row number of each partition in family ordered by the created_date, and then filter by the the three families you are interested in:
with row_window as (
select
id,
family,
env_xml_path,
created_date,
row_number() over (partition by family order by created_date asc) as rn
from <your_table>
where family in ('CRM', 'SCM', 'IC')
)
select
id,
family,
env_xml_path,
created_date
from row_window
where rn = 1
Output:
ID
FAMILY
ENV_XML_PATH
CREATED_DATE
15826841
CRM
path1.xml
03-09-22 6:50:34
15826856
SCM
path3.xml
03-10-22 7:12:20
15826786
IC
path4.xml
02-10-22 12:50:52
The question doesn't really specify what 'first' means, but I assume it means the first to be added in the table, aka the person whose date is the oldest. Try this code:
SELECT DISTINCT * FROM (yourTable) WHERE Family = 'CRM' OR
Family = 'SCM' OR Family = 'IC' ORDER BY Created_Date ASC FETCH FIRST (number) ROWS ONLY;
What it does:
Distinct - It selects different rows, which means you won't get same type of rows at the top.
Where - checks if certain condition is true
OR - it means that the select should choose rows that match those requirements. In the current situation the distinct clause means that same rows won't repeat, so you won't be getting 2 different 'CRM' family names, so it will find the first 'CRM' then the first 'SCM' and so on.
ORDER BY - orders the column in specified order. In the current one, if first rows mean the oldest, then by ordering them by date and using ASC the oldest(aka smallest date) will be at the top.
FETCH FIRST (number) ROWS ONLY - It selects only the very first couple of rows you want. For example if you need 3 different 'first' rows you need to get FETCH FIRST 3 ROWS ONLY. Combined with the distinct word it will only show 3 different rows.
If anyone can help me figure out where I am going wrong with this SQL that would be great. Please see my attempt to answer it below. I have answer how I think it should be answered but I am very confused by the exam advice below, which says I should use a SUM function? I have googled this and I do not see how a SUM function can help here when I need get the product of two values in this case. Or am I missing something major?
Question: TotalValue is a column in Order relation that contains derived data representing total value (amount) of each order. Write a SQL SELECT statement that computes a value for this column.
My answer:
SELECT Product.ProductPrice * OrderLine.QuantityOrdered AS Total_Value
FROM Product,
OrderLine
GROUP BY Product;
Advice from exam paper:
This is a straightforward question. Tip: you need to use the SUM function. Also, note that you can take the sum of various records set using the GROUP BY clause.
Ok your question became a lot clearer once I clicked on the the hyperlink (blue text).
Each order is going to be made up of a quantity of 1 or more products.
So there could be 3 Product A and 5 Product B etc.
So you have to get the total for each product which is your Price * Quantity, but then you need to add them all together which is where the SUM comes in.
Example:
3 * ProductA Price (e.g. €5) = 15
5 * ProductB Price (e.g. €4) = 20
Total Value = 35
So you need to use the Product, Order and OrderLine tables.
Something like (I haven't tested it):
SELECT SUM(Product.ProductPrice * OrderLine.QuantityOrdered) FROM Product, Order, OrderLine
WHERE Order.OrderID = OrderLine.OrderID
AND Product.ProductID = OrerLine.ProductID
GROUP BY Order.OrderID
This should return rows containing the totalValue for each order - the GROUP BY clause causes the SUM to SUM over each group - not the entire rows.
For a single order you would need add (before the GROUP BY) "AND Order.OrderID = XXXXX" where XXXXX is the actual orders OrderId.
I've got a database that holds information about volunteers and their participation in a range of events.
The following query gives me a list of their names and total attendances
SELECT
volunteers.last_name,
volunteers.first_name,
count (bookings.id)
FROM
volunteers,
bookings
WHERE
volunteers.id = bookings.volunteer_id
GROUP BY
volunteers.last_name,
volunteers.first_name
I want the result table to show the distinct number of attendances and how many there are of each; So if five people did one event it'd display 1 in the first column and 5 in the second and so on.
Thanks
If I understand correctly, you want what I call a "histogram of histograms" query:
select numvolunteers, count(*) as numevents, min(eventid), max(eventid)
from (select b.eventid, count(*) as numvolunteers
from bookings b
group by b.eventid
) b
group by numvolunteers
order by numvolunteers;
The first column is the number of volunteers booked for an "event". The second is the number of events where this occurs. The last two columns are just examples of events that have the given number of volunteers.
Salam, (Greetings) to all.
Intro:
I am working on a Student Examination System, where Students appear and pass or fail or absent.
Problem:
I am tasked to fetch their Summary of Status. you may say a Result Card which should print their very last status of a Subject.
Below is a sample of the data where a student has appeared many times, in different sessions. I have highlighted one subject in which a student has appeared three times.
Now, I write the following Query which extract the same result as the picture above:
SELECT DISTINCT
gr.STUDKEY,gr.SUBJECT_ID, gr.SUBJECT_DESC,gr.MARKS,
gr.PASSFAIL, gr.GRADE,max(gr.SESSION_ID), gr.LEVEL_ID
FROM RESULT gr
WHERE gr.STUDKEY = '0100106524'
GROUP BY gr.STUDKEY,gr.SUBJECT_ID, gr.SUBJECT_DESC,gr.MARKS,
gr.PASSFAIL, gr.GRADE, gr.LEVEL_ID
Desired:
I want to get only the last status of a subject in which a student has appeared.
Help is requested. Thanks in advanced.
Regards
I am using sql-server-2008.
This won't work because you include fields like gr.MARKS and gr.GRADE in the group by and in the select which means that the query might return more than 1 record for each session id while their grade or marks is different.
SELECT
gr.STUDKEY,gr.SUBJECT_ID, gr.SUBJECT_DESC,
gr.PASSFAIL, gr.GRADE,gr.SESSION_ID, gr.LEVEL_ID
FROM RESULT gr
JOIN (SELECT MAX(SessionId) as sessionId, STUDKEY
FROM RESULT
GROUP BY STUDKEY ) gr1 ON gr1.sessionId=gr.sessionid AND gr1.STUDKEY =gr.STUDKEY
Hopefully there is a date field, or something that indicates the order of the students appearances in this class. Use that to order your query in descending order, so that the most recent occurrence is the first record, then specifiy "Top 1" which will then give you only the most recent record for that student, which will include in his most recent status.
SELECT TOP 1
gr.STUDKEY,gr.SUBJECT_ID, gr.SUBJECT_DESC,gr.MARKS,
gr.PASSFAIL, gr.GRADE,gr.SESSION_ID, gr.LEVEL_ID
FROM RESULT gr
WHERE gr.STUDKEY = '0100106524'
ORDER BY gr.Date DESC //swap "Date" out for your field indicating the sequence.
or use a Group by with MAX(Date) if you're looking for multiple classes with the same student at the same time.
Imagine an auction (ebay auction, for example). You create an auction, set the start bidding value, let's say, 5 dollars. This gets stored as a minimal bid value to the auctions table.At this point, the current bid value of this auction is 5 dollars.
Now, if someone bids to your auction, let's say, 10 dollars, this gets stored to the bids table.At this point, the current bid value of this auction is 10 dollars.
Now let's imagine you want to retrieve 5 cheapest auctions. You will write a query like this:
SELECT
`auction_id`,
`auction_startPrice`,
MAX(bids.bid_price) as `bid_price`
FROM
`auctions`
LEFT JOIN `bids` ON `auctions`.`auction_id`=`bids`.`bid_belongs_to_auction`
GROUP BY `auction_id`
LIMIT 5
Pretty simple, and it works! But now you need to add an ORDER BY clause to the query. The problem is, however, that we want to ORDER BY either by auctions.auction_startPrice or by bid_price, depending on whichever of this is higher, as explained in the first paragraphs.
Can this be understood? I know how to do this using 2 queries, but I am hoping it can be done with 1 query.
Thanks!
EDIT: Just a further explanation to help you imagine the problem. If I set ORDER BY auction_startPrice ASC, then I will get 5 auctions with their lowest initial bid price, but what if there are already bids placed on those auctions? Then their current lowest price is equal to those bids, NOT to the start price, therefore my query is wrong.
SELECT
`auction_id`,
`auction_startPrice`,
`bid_price`
FROM
(
SELECT
`auction_id`,
`auction_startPrice`,
MAX(bids.bid_price) as `bid_price`,
IF(MAX(bids.bid_price)>`auction_startPrice`,
MAX(bids.bid_price),
`auction_startPrice`) higherPrice
FROM
`auctions`
LEFT JOIN `bids` ON `auctions`.`auction_id`=`bids`.`bid_belongs_to_auction`
GROUP BY `auction_id`
) X
order by higherPrice desc
LIMIT 5;
Note:
In the inner query, an extra column is created, named 'higherPrice'
The IF function compares the MAX(bid_price) column against the startprice, and only if the Max-bid is not null (implicitly required in comparison) and greater than start price, then the Max-bid becomes the value in the higherPrice column. Otherwise, it will contain the start price.
The outer query merely makes use of the columns from the inner query, ordering by the higherPrice
I'm not sure which database you're using but look at this example:
http://www.extremeexperts.com/sql/articles/CASEinORDER.aspx
SELECT
`auction_id`,
`auction_startPrice`,
MAX(bids.bid_price) as `bid_price`
FROM
`auctions`
LEFT JOIN `bids` ON `auctions`.`auction_id`=`bids`.`bid_belongs_to_auction`
GROUP BY `auction_id`
ORDER BY CASE WHEN `auction_startPrice` > isnull(MAX(bids.bid_price),0) then `auction_startPrice` else MAX(bids.bid_price) end
LIMIT 5