i have a table with a bunch of customer IDs. in a customer table is also these IDs but each id can be on multiple records for the same customer. i want to select the most recently used record which i can get by doing order by <my_field> desc
say i have 100 customer IDs in this table and in the customers table there is 120 records with these IDs (some are duplicates). how can i apply my order by condition to only get the most recent matching records?
dbms is sql server 2000.
table is basically like this:
loc_nbr and cust_nbr are primary keys
a customer shops at location 1. they get assigned loc_nbr = 1 and cust_nbr = 1
then a customer_id of 1.
they shop again but this time at location 2. so they get assigned loc_nbr = 2 and cust_Nbr = 1. then the same customer_id of 1 based on their other attributes like name and address.
because they shopped at location 2 AFTER location 1, it will have a more recent rec_alt_ts value, which is the record i would want to retrieve.
You want to use the ROW_NUMBER() function with a Common Table Expression (CTE).
Here's a basic example. You should be able to use a similar query with your data.
;WITH TheLatest AS
(
SELECT *, ROW_NUMBER() OVER (PARTITION BY group-by-fields ORDER BY sorting-fields) AS ItemCount
FROM TheTable
)
SELECT *
FROM TheLatest
WHERE ItemCount = 1
UPDATE: I just noticed that this was tagged with sql-server-2000. This will only work on SQL Server 2005 and later.
Since you didn't give real table and field names, this is just psuedo code for a solution.
select *
from customer_table t2
inner join location_table t1
on t1.some_key = t2.some_key
where t1.LocationKey = (select top 1 (LocationKey) as LatestLocationKey from location_table where cust_id = t1.cust_id order by some_field)
Use an aggregate function in the query to group by customer IDs:
SELECT cust_Nbr, MAX(rec_alt_ts) AS most_recent_transaction, other_fields
FROM tableName
GROUP BY cust_Nbr, other_fields
ORDER BY cust_Nbr DESC;
This assumes that rec_alt_ts increases every time, thus the max entry for that cust_Nbr would be the most recent entry.
By using time and date we can take out the recent detail for the customer.
use the column from where you take out the date and the time for the customer.
eg:
SQL> select ename , to_date(hiredate,'dd-mm-yyyy hh24:mi:ss') from emp order by to_date(hiredate,'dd-mm-yyyy hh24:mi:ss');
Related
I have two tables in an Oracle Database, one of which is all the purchases done by all the customers over many years (purchase_logs). It has a unique purchase_id that is paired with a customer_id.The other table contains the user info of all the customers. Both have a common key of customer_id.
I want to display the user info of customers who have more than 1 unique item (NOT the item quantity) purchased in any month (i.e if A customer bought 4 unique items in february 2020 they would be valid as well as someone who bought 2 items in june). I was wondering what should my correct approach be and also how to correct execute that approach.
The two approaches that I can see are
Approach 1
Count the overall number of purchases done by all customers, filter the ones that are greater than 1 and then check if they any of them were done within a month.
Use this as a subquery in the where clause of the main query for retrieving the customer info for all the customer_id which match this condition.
This is what i've done so far,this retrieves the customer ids of all the customers who have more than 1 purchases in total. But I do not understand how to filter out all the purchases that did not occur in a single arbitrary month.
SELECT * FROM customer_details
WHERE customer_id IN (
SELECT cust_id from purchase_logs
group by cust_id
having count(*) >= 2);
Approach 2
Create a temporary table to Count the number of monthly purchases of a specific user_id then find the MAX() of the whole table and check if that MAX value is bigger than 1 or not. Then if it is provide it as true for the main query's where clause for the customer_info.
Approach 2 feels like the more logical option but I cannot seem to understand how to write the proper subquery for it as the command MAX(COUNT(customer_id)) from purchase_logs does not seem to be a valid query.
This is the DDL diagram.
This is the Sample Data of Purchase_logs
Customer_info
and Item_info
and the expected output for this sample data would be
It is certainly possible that there is a simpler approach that I am not seeing right now.
Would appreciate any suggestions and tips on this.
You need this query:
SELECT DISTINCT cust_id
FROM purchase_logs
GROUP BY cust_id, TO_CHAR(purchase_date, 'YYYY-MON')
HAVING COUNT(DISTINCT item_id) > 1;
to get all the cust_ids of the customers who have more than 1 unique item purchased in any month and you can use with the operator IN:
SELECT *
FROM customer_details
WHERE customer_id IN (
SELECT DISTINCT cust_id -- here DISTINCT may be removed as it does not make any difference when the result is used with IN
FROM purchase_logs
GROUP BY cust_id, TO_CHAR(purchase_date, 'YYYY-MON')
HAVING COUNT(DISTINCT item_id) > 1
);
One approach might be to try
with multiplepurchase as (
select customer_id,month(purchasedate),count(*) as order_count
from purchase_logs
group by customer_id,month(purchasedate)
having count(*)>=2)
select customer_id,username,usercategory
from mutiplepurchase a
left join userinfo b
on a.customer_id=b.customer_id
Expanding on #MT0 answer:
SELECT *
FROM customer_details CD
WHERE exists (
SELECT cust_id
FROM purchase_logs PL
where CD.customer_id = PL.customer_id
GROUP BY cust_id, item_id, to_char(purchase_date,'YYYYMM')
HAVING count(*) >= 2
);
I want to display the user info of customers who have more than 1 purchases in a single arbitrary month.
Just add a WHERE filter to your sub-query.
So assuming that you wanted the month of July 2021 and you had a purchase_date column (with a DATE or TIMESTAMP data type) in your purchase_logs table then you can use:
SELECT *
FROM customer_details
WHERE customer_id IN (
SELECT cust_id
FROM purchase_logs
WHERE DATE '2021-07-01' <= purchase_date
AND purchase_date < DATE '2021-08-01'
GROUP BY cust_id
HAVING count(*) >= 2
);
If you want the users where they have bought two-or-more items in any single calendar month then:
SELECT *
FROM customer_details c
WHERE EXISTS (
SELECT 1
FROM purchase_logs p
WHERE c.customer_id = p.cust_id
GROUP BY cust_id, TRUNC(purchase_date, 'MM')
HAVING count(*) >= 2
);
I have an oracle sql database consisting of three tables and I was wondering,
What is the most efficient subquery that can be written to retrieve the information of the customer stored in the table customer_info who has performed the highest amount of purchases in total.(The purchase data is in the table purchase_logs). i.e the number of transactions one customer has performed NOT the quantity of the items purchased.
i.e my aim is to retrieve the customer details of the customer witht he highest amount of purchases done.
I have 3 tables one for the customer_info, one as the purchase_logs and the last one being the item_info.
My current Approach
SELECT * FROM customer_info
WHERE customer_id = (SELECT cust_id
FROM purchase_logs
GROUP BY cust_id
ORDER BY COUNT(*)
DESC LIMIT 1);
This doesn't seem to give me any results at all unfortunately.
This is my Database Schema along with the Sample Data of purchase_logs, customer_info, item_info and the Expected Output
I would really appreciate any help in understanding what the proper approach to solving this problem would be.
There is no limit 1 in Oracle SQL, use row limiting clause instead (fetch first in the example below):
SELECT *
FROM
(SELECT cust_id, count(*) cnt
FROM purchase_logs
GROUP BY cust_id
ORDER BY cnt desc
fetch first 1 row only with ties
) vc
join customer_info
on customer_id = vc.cust_id;
Select id, name , max(modify_time)
from customer
group by id, name
but I get all records.
Order by modify_time desc and use row_number to number the row for id,name combination.Then select each combination with row_number = 1
select id,modify_time,name
from (
select id,modify_time,name,row_number() over(partition by id order by modify_time desc) as r_no
from customer
) a
where a.r_no=1
Ids are unique, which means grouping them by the id, will result in the same table.
My suggestion would be, to order the table by "modify_time" descending and limit the result to 1 (Maybe something like the following):
Select id, name modify_time from customer ORDER BY modify_time DESC limit 1
The reason you are getting the whole table as a result is because you are grouping by id AND name. That means every unique combination of id and name is returned. And since all names per id are different, the whole table is returned.
If you want the last modification per id (or name) you should only group by id (or name respectively).
I need to perform TREAMMEAN in Access, which does not have this function.
In a table I have many Employees, each has many records.
I need to TRIMMEAN Values for each Employee separately.
Following queries perform TOP 10 percent for all records:
qry_data_TOP10_ASC
qry_data_TOP10_DESC
unionqry_TOP10_ASCandDESC
qry_data_ALL_minus_union_qry
After that, I can use Avg (Average).
But I don't know how to do it for each employee.
Visualization:
Note:
This question is edited to simplify problem.
You don't really give information in your pseudo code about your data fields but using your example that DOES have basic field information I can suggest the following should work as you described
It assumes field1 is your unique record ID - but you make no mention of which fields are keys
SELECT AVG(qry_data.field2) FROM qry_data WHERE qry_data.field1 NOT IN
(SELECT * FROM
(SELECT TOP 10 PERCENT qry_data.field1, qry_data.field2
FROM qry_data
ORDER BY qry_data.field2 ASC)
UNION
(SELECT TOP 10 PERCENT qry_data.field1, qry_data.field2
FROM qry_data
ORDER BY qry_data.field2 DESC)
)
This should give you what you want, the two sub-queries should correlate the TOP 10s (ascending and descending) for every employee. The two NOT INs should then remove those from the Table1 records and then you group the Employees and Average the Scores.
SELECT Table1.Employee, AVG(Table1.Score) AS AvgScore
FROM Table1
WHERE ID NOT IN
(
SELECT TOP 10 ID
FROM Table1 a
WHERE a.Employee = Table1.Employee
ORDER BY Score ASC, Employee, ID
)
AND ID NOT IN
(
SELECT TOP 10 ID
FROM Table1 b
WHERE b.Employee = Table1.Employee
ORDER BY Score DESC, Employee, ID
)
GROUP BY Table1.Employee;
I am trying to write a script that will return the latest values for a unique documentid-physician-patient triplet. I need the script to act similar to a group by statement, except group by only works with one column at a time. I need to date and status information for only the most recent unique triplet. Please let me know what you will need to see from me to help. Here is the current, very bare, statement:
SELECT
TransmissionSend.CreateTimestamp,
TransmissionSendItem.Status,
TransmissionSendItem.PhysicianId,
TransmissionSendItem.DocumentIdDisplay,
Utility.SqlFunctions_NdnListToAccountList(TransmissionSendItem.NdocNum) AS AccountNum
FROM
Interface_SFAX.TransmissionSend,
Interface_SFAX.TransmissionSendItem
WHERE
TransmissionSend.ID = TransmissionSendItem.childsub --I don't know exactly what this does, I did not write this script. It must stay here though for the exact results.
ORDER BY TransmissionSend.CreateTimestamp DESC -- In the end, each latest result of the unique triplet will be ordered from most recent to oldest in return
My question is, again, how can I limit results to only the latest status for each physician id, document id, and account number combination?
First select the MAX(date) with the documentid GROUP BY documentid then select all data from the table by the first select result for example with an inner join.
SELECT table.additionalData, J.id, J.date
FROM table
INNER JOIN (SELECT id, MAX(date) AS date
FROM table GROUP BY id) AS J
ON J.id = table.id
AND J.date /* this is the max date */ = table.date