I am trying to pull some specific information from an access control database.
I have a query providing results spanning several days. For a specific day, I need to get the first record of each person for that specific day. I have totally muddled the entire bit, hence my questions
This is the code used to pull the initial query
Select
Message.TimeStamp_SPM,
Message.FirstName,
Message.LastName,
Message.CardNumber,
Message.MessageDescription,
Message.Description,
Department.Description As Description1
From
Message Inner Join
CardHolder On CardHolder.CardHolderID = Message.CardHolderID Inner Join
Department On CardHolder.DepartmentID = Department.DepartmentID
Where
Message.TimeStamp_SPM > Convert(datetime,'2021-03-02',120) And
Message.TimeStamp_SPM < Convert(datetime,'2021-03-03',120) And
Message.Description Not Like '%Truck%'
From this query I need to display the obtain the first record of each person for that specific date. Any advice on the most efficient way to obtain the desired result?
From this query I need to display the obtain the first record of each person for that specific date.
Assuming "person" is CardHolderId, then include that in your query. You can then use window functions to get the most recent record for each CardHolderId:
with cte as (
<your query here with CardHolderId>
)
select cte.*
from (select cte.*,
row_number() over (partition by CardHolderID order by TimeStamp_SPM desc) as seqnum
from cte
) cte
where seqnum = 1;
Related
I have three T-SQL statements that I'd like to combine into one, so it is just a single call to the database, not three.
SELECT * FROM Clients
The first one, selects every client from the Clients table.
SELECT * FROM History
The second one, selects all the history entries from the History table. I then use some code to find the first history for each client. i.e. first history in the table for ClientID gets set into the HasHistory column for that ClientID.
SELECT * FROM Actions
The final one, I get all the actions from the action table. I then use some code to find the last action for each client. i.e. last action in the table for ClientID gets set into the LastAction column for that ClientID.
So I'm wondering if there is a way to write an SQL statement like this for example? Note this is not real SQL, just pseudo code to illustrate what I'm trying to achieve.
SELECT *
FROM Clients
AND
SELECT First History Row
FROM History
WHERE History.ClientID = Clients.ClientID
AND
SELECT Last Action Row
FROM Actions
WHERE Actions.ClientID = Clients.ClientID
There are a number of ways you can do this, but here is one example. I'll work on it a bit at a time to explain what we are doing. You haven't shown us the table design, so the column names are a guess, but you should get the idea.
First, you have to somehow mark which history rows you care about. One way to do this is to do a query that puts an order number on every history row, that starts from 1 with every new client, and orders them by date. This way, the first history row for each client (the one you want) always has a row number of one. This would look something like
SELECT
*,
ROW_NUMBER() OVER (PARTITION BY clientID ORDER BY historyDate) AS orderNo
FROM
History
You would do something similar with actions, except you want the latest action, not the first one, so your order by column has to be in reverse order - you do this by telling the ORDER BY to use descending order, something like this
SELECT
*,
ROW_NUMBER() OVER (PARTITION BY clientID ORDER BY actionDate DESC) AS orderNo
FROM Actions
You should now have two queries where the only rows you want are marked with a order number of one. What you do now is start with your first query, and join to these other two queries so that you only join to the orderno = 1 rows. Then all the data you want will be available in one row. You have to decide which join type to use - an inner join will only return Clients that actually have a history and an action. If you want to see clients that have no rows at all in the other tables, you need to use a left outer join. But your final query (you only need this one) will look something like
SELECT
C.*, H.*, A.*
FROM
Clients C
LEFT OUTER JOIN
(SELECT
*,
ROW_NUMBER() OVER (PARTITION BY clientID ORDER BY historyDate) AS orderNo
FROM History) H ON H.clientID = C.clientID AND H.orderNo = 1
LEFT OUTER JOIN
(SELECT
*,
ROW_NUMBER() OVER (PARTITION BY clientID ORDER BY actionDate DESC) AS orderNo
FROM Actions) A ON A.clientID = C.clientID AND A.orderNo = 1
What this says is: take Clients (which we'll call C), then for each row, try and join to (match a row from) the History query we looked at above (which we'll call H) where the client ID is the same and the orderNo is 1 - ie the first history row. It also does the same for the Actions query.
I have a table with real-time scanning data from our employees. As you can see, each boxes can be scanned multiple times, even employees can scan the boxes multiple time for one status.
I am trying to pull the latest record for each box, but the status for the latest record should be "Refused"
From the picture, as you can see, although Carton 1234 has a record with status "Refused", but this record is not the last one, so I don’t need this. And the carton 1235 is what I need.
I don’t want to use a window function to rank each record in the table first, because I have a lot of rows in the table, and I think it will be time consuming.
So is there any better way to achieve my goal?
Supposing that you don't really need a PL/SQL solution. Here is SQL only:
This is a solution without window functions:
select *
from mytable
where (carton_id, scantime) in
(
select carton_id, max(scantime)
from mytable
group by carton_id
having max(status) keep (dense_rank last order by scantime) = 'Refused'
);
But I don't think that this is superior to using a window function. So you can just as well try
select *
from
(
select mytable.*, max(scantime) over (partition by carton_id) as max_scantime
from mytable
group by carton_id
)
where scantime = max_scantime and status = 'Refused';
Here is one method:
select t.*
from t
where t.status = 'Refused' and
t.scantime = (select max(t2.scantime) from t t2 where t2.carton_id = t.carton_id);
I have a table Orders(id_trip, id_order), table Trip(id_hotel, id_bus, id_type_of_trip) and table Hotel(id_hotel, name).
I would like to get name of the most frequent hotel in table Orders.
SELECT hotel.name from Orders
JOIN Trip
on Orders.id_trip = Trip.id_hotel
JOIN hotel
on trip.id_hotel = hotel.id_hotel
FROM (SELECT hotel.name, rank() over (order by cnt desc) rnk
FROM (SELECT hotel.name, count(*) cnt
FROM Orders
GROUP BY hotel.name))
WHERE rnk = 1;
The "most frequently occurring value" in a distribution is a distinct concept in statistics, with a technical name. It's called the MODE of the distribution. And Oracle has the STATS_MODE() function for it. https://docs.oracle.com/cd/B19306_01/server.102/b14200/functions154.htm
For example, using the EMP table in the standard SCOTT schema, select stats_mode(deptno) from scott.emp will return 30 - the number of the department with the most employees. (30 is the department "name" or number, it is NOT the number of employees in that department!)
In your case:
select stats_mode(h.name) from (the rest of your query)
Note: if two or more hotels are tied for "most frequent", then STATS_MODE() will return one of them (non-deterministic). If you need all the tied values, you will need a different solution - a good example is in the documentation (linked above). This is a documented flaw in Oracle's understanding and implementation of the statistical concept.
Use FIRST for a single result:
SELECT MAX(hotel.name) KEEP (DENSE_RANK FIRST ORDER BY cnt DESC)
FROM (
SELECT hotel.name, COUNT(*) cnt
FROM orders
JOIN trip USING (id_trip)
JOIN hotel USING (id_hotel)
GROUP BY hotel.name
) t
Here is one method:
select name
from (select h.name,
row_number() over (order by count(*) desc) as seqnum -- use `rank()` if you want duplicates
from orders o join
trip t
on o.id_trip = t.id_trip join -- this seems like the right join condition
hotels h
on t.id_hotel = h.id_hotel
) oth
where seqnum = 1;
** Getting the most recent statistical mode out of a data sample **
I know it's more than a year, but here's my answer. I came across this question hoping to find a simpler solution than what I know, but alas, nope.
I had a similar situation where I needed to get the mode from a data sample, with the requirement to get the mode of the most recently inserted value if there were multiple modes.
In such a case neither the STATS_MODE nor the LAST aggregate functions would do (as they would tend to return the first mode found, not necessarily the mode with the most recent entries.)
In my case it was easy to use the ROWNUM pseudo-column because the tables in question were performance metric tables that only experienced inserts (not updates)
In this oversimplified example, I'm using ROWNUM - it could easily be changed to a timestamp or sequence field if you have one.
SELECT VALUE
FROM
(SELECT VALUE ,
COUNT( * ) CNT,
MAX( R ) R
FROM
( SELECT ID, ROWNUM R FROM FOO
)
GROUP BY ID
ORDER BY CNT DESC,
R DESC
)
WHERE
(
ROWNUM < 2
);
That is, get the total count and max ROWNUM for each value (I'm assuming the values are discrete. If they aren't, this ain't gonna work.)
Then sort so that the ones with largest counts come first, and for those with the same count, the one with the largest ROWNUM (indicating most recent insertion in my case).
Then skim off the top row.
Your specific data model should have a way to discern the most recent (or the oldest or whatever) rows inserted in your table, and if there are collisions, then there's not much of a way other than using ROWNUM or getting a random sample of size 1.
If this doesn't work for your specific case, you'll have to create your own custom aggregator.
Now, if you don't care which mode Oracle is going to pick (your bizness case just requires a mode and that's it, then STATS_MODE will do fine.
Medical records in my Crystal Report are sorted in this order:
...
Group 1: Score [Level of Risk]
Group 2: Patient Name
...
Because patients are sorted by Score before Name, the report pulls in multiple entries per patient with varying scores - and since duplicate entries are not always adjacent, I can't use Previous or Next to suppress them. To fix this, I'd like to only display the latest entry for each patient based on the Assessment Date field - while maintaining the above order.
I'm convinced this behavior can be implemented with a custom SQL command to only pull in the latest entry per patient, but have had no success creating that behavior myself. How can I accomplish this compound sort?
Current SQL Statement in use:
SELECT "EpisodeSummary"."PatientID",
"EpisodeSummary"."Patient_Name",
"EpisodeSummary"."Program_Value"
"RiskRating"."Rating_Period",
"RiskRating"."Assessment_Date",
"RiskRating"."Episode_Number",
"RiskRating"."PatientID",
"Facility"."Provider_Name",
FROM (
"SYSTEM"."EpisodeSummary"
"EpisodeSummary"
LEFT OUTER JOIN "FOOBARSYSTEM"."RiskAssessment" "RiskRating"
ON (
("EpisodeSummary"."Episode_Number"="RiskRating"."Episode_Number")
AND
("EpisodeSummary"."FacilityID"="RiskRating"."FacilityID")
)
AND
("EpisodeSummary"."PatientID"="RiskRating"."PatientID")
), "SYSTEM"."Facility" "Facility"
WHERE (
"EpisodeSummary"."FacilityID"="Facility"."FacilityID"
)
AND "RiskRating"."PatientID" IS NOT NULL
ORDER BY "EpisodeSummary"."Program_Value"
The SQL code below may not be exactly correct, depending on the structure of your tables. The code below assumes the 'duplicate risk scores' were coming from the RiskAssessment table. If this is not correct, the code may need to be altered.
Essentially, we create a derived table and create a row_number for each record, based on the patientID and ordered by the assessment date - The most recent date will have the lowest number (1). Then, on the join, we restrict the resultset to only select record #1 (each patient has its own rank #1).
If this doesn't work, let me know and provide some table details -- Should the Facility table be the starting point? are there multiple entries in EpisodeSummary per patient? thanks!
SELECT es.PatientID
,es.Patient_Name
,es.Program_Value
,rrd.Rating_Period
,rrd.Assessment_Date
,rrd.Episode_Number
,rrd.PatientID
,f.Provider_Name
FROM SYSTEM.EpisodeSummary es
LEFT JOIN (
--Derived Table retreiving highest risk score for each patient)
SELECT PatientID
,Assessment_Date
,Episode_Number
,FacilityID
,Rating_Period
,ROW_NUMBER() OVER (
PARTITION BY PatientID ORDER BY Assessment_Date DESC
) AS RN -- This code generates a row number for each record. The count is restarted for every patientID and the count starts at the most recent date.
FROM RiskAssessment
) rrd
ON es.patientID = rrd.patientid
AND es.episode_number = rrd.episode_number
AND es.facilityid = rrd.facilityid
AND rrd.RN = 1 --This only retrieves one record per patient (the most recent date) from the riskassessment table
INNER JOIN SYSTEM.Facility f
ON es.facilityid = f.facilityid
WHERE rrd.PatientID IS NOT NULL
ORDER BY es.Program_Value
I have 4 tables with the following relevant information I want to retrieve.
Table: Staff_profile (STAFF_ID, STAFF_USERNAME, STAFF_NAME, STAFF_JOB_ID, STAFF_FACULTY_ID, STAFF_OFF_TEL, STAFF_EMAIL) - holds staff information
Table: RFMUSERHISTORY (uh_staff_id, UH_DATETIME) - holds login history
Table: RFMUSERROLEJOBMAP (role_id, job_id ) - maps role-2-job [this is because job table pre-exists and this new app is only picking certain job ids to use against its own roles table
Table: RFMUSERROLE (USERROLE_CODE, USERROLE_ID) - holds user roles information
Now I want to get the last login (max date for that user in userhistory) details including role and staff details for any particular person who logs in. I have had trouble with my code and finally just resorted to selecting all the records for that user with the UH_datetime ordered desc so I can pick that latest topmost record.
Here is my current code (very inefficient as described above):
SELECT a.STAFF_ID, a.STAFF_USERNAME, a.STAFF_NAME, a.STAFF_JOB_ID, a.STAFF_FACULTY_ID,
a.STAFF_OFF_TEL, a.STAFF_EMAIL, to_CHAR(b.UH_DATETIME,'Dy DD-MM-YYYY HH24:MI:SS')
AS UH_DATETIME, e.USERROLE_CODE, e.USERROLE_ID
FROM STAFF_PROFILE a
LEFT JOIN RFMUSERHISTORY b ON STAFF_ID=b.uh_staff_id
LEFT JOIN RFMUSERROLEJOBMAP d ON a.STAFF_JOB_ID=d.job_id
LEFT JOIN RFMUSERROLE e ON d.role_id=e.userrole_id
WHERE STAFF_ID=:eid1 ORDER BY b.UH_DATETIME DESC
You could use an analytic function to rank the rows and then select the most recent one. If you're really just selecting the data for a single STAFF_ID, this is probably no more efficient than nesting your original query in an outer query that selects the row using a ROWNUM predicate. If you are selecting the data for multiple staff members, however, this should be more efficient.
SELECT *
FROM (
SELECT a.STAFF_ID,
a.STAFF_USERNAME,
a.STAFF_NAME,
a.STAFF_JOB_ID,
a.STAFF_FACULTY_ID,
a.STAFF_OFF_TEL,
a.STAFF_EMAIL,
to_CHAR(b.UH_DATETIME,'Dy DD-MM-YYYY HH24:MI:SS') AS UH_DATETIME,
e.USERROLE_CODE,
e.USERROLE_ID,
dense_rank() over (partition by a.staff_id order by b.uh_datetime desc) rnk
FROM STAFF_PROFILE a
LEFT JOIN RFMUSERHISTORY b ON STAFF_ID=b.uh_staff_id
LEFT JOIN RFMUSERROLEJOBMAP d ON a.STAFF_JOB_ID=d.job_id
LEFT JOIN RFMUSERROLE e ON d.role_id=e.userrole_id
WHERE STAFF_ID=:eid1
)
WHERE rnk = 1
Oracle doesn't send rows over the network before you ask for them. If your client code only request the first row, your query should be efficient enough.
Another option is to limit Oracle to one row with rownum:
where rownum = 1