I've got a problem constructing a somewhat advanced query.
I have two views - A and B where B is the child of A.
This relationship is handled by
A vw_StartDate.MapToID
=
B vw_TrackerFeaturesBasic.StartDateMapToID.
What I need to do is grab every parent A and a count of the LATEST added children B.
This is a query that gets the latest children B in a SSRS-report: (This does not use A at all!):
/****** Selecting the incomplete, applicable issues of the latest insert. ******/
SELECT DISTINCT [TRK_Feature_LKID]
,[TrackerGroupDescription]
,[ApplicableToProject]
,[ReadyForWork]
,[DateStamp]
FROM [vw_TRK_TrackerFeaturesBasic] as temp
WHERE ApplicableToProject = 1
AND DateStamp = (SELECT MAX(DateStamp) from [vw_TRK_TrackerFeaturesBasic] WHERE [TRK_StartDateID] = #WSCTrackerID AND StartDateMapToID = #HierarchyID AND [TRK_Feature_LKID] = temp.TRK_Feature_LKID )
ORDER BY DateStamp DESC
I've tried a few different ways, but I can't figure out how to get the latest added children from the subquery (I've mainly used a subquery nestled in a COUNT / Case + SUM).
Since SQL Server doesn't really allow us to use aggregate functions in aggregate functions I'm not sure how to get the latest added item in a subquery as the subquery most likely has to be nested in a COUNT or something similar.
Below is a version I'm working on (doesn't work):
Column 'vw_TRK_TrackerFeaturesBasic.StartDateMapToID' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.
SELECT b.TRK_StartDateID
,(SELECT COUNT(b.TRK_Feature_LKID) FROM b )
FROM vw_TRK_StartDate as a
LEFT JOIN vw_TRK_TrackerFeaturesBasic as b
ON b.StartDateMapToID = a.MapToID AND b.DateStamp = (SELECT MAX(DateStamp) FROM [vw_TRK_TrackerFeaturesBasic] WHERE [TRK_StartDateID] = 47 AND [StartDateMapToID] = 13)
WHERE MapToId = 13
--(SELECT MAX(DateStamp) from [vw_TRK_TrackerFeaturesBasic] WHERE [TRK_StartDateID] = #WSCTrackerID AND StartDateMapToID = #HierarchyID AND [TRK_Feature_LKID] = temp.TRK_Feature_LKID
GROUP BY b.TRK_StartDateID
Your question is a bit hard to follow, because I don't see a relationship between your queries and this request:
What I need to do is grab every parent A and a count of the LATEST
added children B.
Focusing on this statement, you can do this readily with window functions:
SELECT b.StartDateMapToID, COUNT(*)
FROM (SELECT tfb.*,
MAX(tfb.DateStamp) OVER (PARTITION BY tfb.StartDateMapToID) as max_DateStamp
FROM vw_TRK_TrackerFeaturesBasic tfb
) tfb
GROUP BY b.StartDateMapToID;
Related
I try to find what I missed in the code to retrieve the value of "Last_Maintenance" in a table called "Interventions".
I try to understand the order rules of SQL and the particularities of subqueries without success.
Did I missed something, something basic or an important step?
---Interventions with PkState "Schedule_Visit" with the Last_Maintenance aggregation
SELECT Interventions.ID AS Nro_Inter,
--Interventions.PlacesList AS Nro_Place,
MaintenanceContracts.Num AS Nro_Contract,
Interventions.TentativeDate AS Schedule_Visit,
--MaintenanceContracts.NumberOfVisits AS Number_Visits_Contracts,
--Interventions.VisitNumber AS Visit_Number,
(SELECT MAX(Interventions.AssignmentDate)
FROM Interventions
WHERE PkState = 'AE4B42CF-0003-4796-89F2-2881527DFB26' AND PkMaintenanceContract IS NOT NULL) AS Last_Maintenance --PkState "Maintenance Executed"
FROM Interventions
INNER JOIN MaintenanceContracts ON MaintenanceContracts.Pk = Interventions.PkMaintenanceContract
WHERE PkState = 'AE4B42CF-0000-4796-89F2-2881527ABC26' AND PkMaintenanceContract IS NOT NULL --PkState "Schedule_Visit"
GROUP BY Interventions.AssignmentDate,
Interventions.ID,
Interventions.PlacesList,
MaintenanceContracts.Num,
Interventions.TentativeDate,
MaintenanceContracts.NumberOfVisits,
Interventions.VisitNumber
ORDER BY Nro_Contract
I try to use GROUP BY and HAVING clause in a sub query, I did not succeed. Clearly I am lacking some understanding.
Output
The output of "Last_Maintenance" is the last date of entire contracts in the DB, which is not the desirable output. The desirable output is to know the last date the maintenance was executed for each row, meaning, for each "Nro-Contract". Somehow I need to aggregate like I did below.
In opposition of what mention I did succeed in another table.
In the table Contracts I did had success as you can see.
SELECT
MaintenanceContracts.Num AS Nro_Contract,
MAX(Interventions.AssignmentDate) AS Last_Maintenance
--MaintenanceContracts.Name AS Place
--MaintenanceContracts.StartDate,
--MaintenanceContracts.EndDate
FROM MaintenanceContracts
INNER JOIN Interventions ON Interventions.PkMaintenanceContract = MaintenanceContracts.Pk
WHERE MaintenanceContracts.ActiveContract = 2 OR MaintenanceContracts.ActiveContract = 1 --// 2 = Inactive; 1 = Active
GROUP BY MaintenanceContracts.Num, MaintenanceContracts.Name,
MaintenanceContracts.StartDate,
MaintenanceContracts.EndDate
ORDER BY Nro_Contract
I am struggling to understanding how nested queries works and how I can leverage in a simple manner the queries.
I think you're mixed up in how aggregation works. The MAX function will get a single MAX value over the entire dataset. What you're trying to do is get a MAX for each unique ID. For that, you either use derived tables, subqueries or windowed functions. I'm a fan of using the ROW_NUMBER() function to assign a sequence number. If you do it correctly, you can use that row number to get just the most recent record from a dataset. From your description, it sounds like you always want to have the contract and then get some max values for that contract. If that is the case, then you're second query is closer to what you need. Using windowed functions in derived queries has the added benefit of not having to worry about using the GROUP BY clause. Try this:
SELECT
MaintenanceContracts.Num AS Nro_Contract,
--MaintenanceContracts.Name AS Place
--MaintenanceContracts.StartDate,
--MaintenanceContracts.EndDate
i.AssignmentDate as Last_Maintenance
FROM MaintenanceContracts
INNER JOIN (
SELECT *
--This fuction will order the records for each maintenance contract.
--The most recent intervention will have a row_num = 1
, ROW_NUMBER() OVER(PARTITION BY PkMaintenanceContract ORDER BY AssignmentDate DESC) as row_num
FROM Interventions
) as i
ON i.PkMaintenanceContract = MaintenanceContracts.Pk
AND i.row_num = 1 --Used to get the most recent intervention.
WHERE MaintenanceContracts.ActiveContract = 2
OR MaintenanceContracts.ActiveContract = 1 --// 2 = Inactive; 1 = Active
ORDER BY Nro_Contract
;
I have a table named Ticket Numbers, which (for this example) contain the columns:
Ticket_Number
Assigned_Group
Assigned_Group_Sequence_No
Reported_Date
Each ticket number could contain 4 rows, depending on how many times the ticket changed assigned groups. Some of these rows could contain an assigned group of "Desktop Support," but some may not. Here is an example:
Example of raw data
What I am trying to accomplish is to get the an output that contains any ticket numbers that contain 'Desktop Support', but also the assigned group of the max sequence number. Here is what I am trying to accomplish with SQL:
Queried Data
I'm trying to use SQL with the following query but have no clue what I'm doing wrong:
select ih.incident_number,ih.assigned_group, incident_history2.maxseq, incident_history2.assigned_group
from incident_history_public as ih
left join
(
select max(assigned_group_seq_no) maxseq, incident_number, assigned_group
from incident_history_public
group by incident_number, assigned_group
) incident_history2
on ih.incident_number = incident_history2.incident_number
and ih.assigned_group_seq_no = incident_history2.maxseq
where ih.ASSIGNED_GROUP LIKE '%DS%'
Does anyone know what I am doing wrong?
You might want to create a proper alias for incident_history. e.g.
from incident_history as incident_history1
and
on incident_history1.ticket_number = incident_history2.ticket_number
and incident_history1.assigned_group_seq_no = incident_history2.maxseq
In my humble opinion a first error could be that I don't see any column named "incident_history2.assigned_group".
I would try to use common table expression, to get only ticket number that contains "Desktop_support":
WITH desktop as (
SELECT distinct Ticket_Number
FROM incident_history
WHERE Assigned_Group = "Desktop Support"
),
Than an Inner Join of the result with your inner table to get ticket number and maxSeq, so in a second moment you can get also the "MAXGroup":
WITH tmp AS (
SELECT i2.Ticket_Number, i2.maxseq
FROM desktop D inner join
(SELECT Ticket_number, max(assigned_group_seq_no) as maxseq
FROM incident_history
GROUP BY ticket_number) as i2
ON D.Ticket_Number = i2.Ticket_Number
)
SELECT i.Ticket_Number, i.Assigned_Group as MAX_Group, T.maxseq, i.Reported_Date
FROM tmp T inner join incident_history i
ON T.Ticket_Number = i.Ticket_Number and i.assigned_group_seq_no = T.maxseq
I think there are several different method to resolve this question, but I really hope it's helpful for you!
For more information about Common Table Expression: https://www.essentialsql.com/introduction-common-table-expressions-ctes/
Can you please tell me what SQL query can I use to change duplicates in one column of my table?
I found these duplicates:
SELECT Model, count(*) FROM Devices GROUP BY model HAVING count(*) > 1;
I was looking for information on exactly how to change one of the duplicate values, but unfortunately I did not find a specific option for myself, and all the more information is all in abundance filled by deleting the duplicate value line, which I don't need. Not strong in SQL at all. I ask for help. Thank you so much.
You can easily use a Window Functions such as ROW_NUMBER() with partitioning option in order to group by Model column to eliminate the duplicates, and then pick the first rows(rn=1) returning from the subquery such as
WITH d AS
(
SELECT *, ROW_NUMBER() OVER (PARTITION BY Model) AS rn
FROM Devices
)
SELECT ID, Model -- , and the other columns
FROM d
WHERE rn = 1
Demo
use exists as follows:
update d
set Model = '-'
from Devices d
where exists (select 1 from device dd where dd.model = d.model and dd.id > d.id)
After the command:
SELECT Model, count (*) FROM Devices GROUP BY model HAVING count (*)> 1;
i get the result:
1895 lines = NULL;
3383 lines with duplicate values;
and all these values are 1243.
after applying your command:
update Devices set
Model = '-'
where id not in
(select
min(Devices .id)
from Devices
group by Devices.Model)
i got 4035 lines changed.
if you count, it turns out, (3383 + 1895) = 5278 - 1243 = 4035
and it seems like everything fits together, the result suits, it works.
I have a table called ArchiveActivityDetails which shows the history of a Customer Repair Order. 1 Repair Order will have many visits (ActivityID) with a Technician allocated depending on who is available for that planned visit.
The system automatically allocates the time that is required for a job but sometimes a job requires longer so we manually ammend jobs.
My initial query from the customer was to pull the manually ammended jobs (ie: jobs where PlannedDuration >=60 minutes) and shows the Technician linked to that manually ammended job.
This report works fine.
My most recent request from the customer is to now ADD a column showing WHO WAS THE PREVIOUS TECHNICIAN linked that the Repair Order.
My collegues suggested I do a Cross Apply going back to the ArchiveActivityDetails table and then show "Previous Tech" but I have not used Cross Apply before and I am struggling with the syntax and unable to get the results I want. In my Cross Apply I used LAG to work out the 'PrevTech' but when pulling it into my main report, I get NULL. So I assume I am not doing the Cross Apply correctly.
DECLARE #DateFrom as DATE = '2019-05-20'
DECLARE #DATETO AS DATE = '2019-07-23'
----------------------------------------------------------------------------------
SELECT
AAD.Date
,ASM.ASM
,A.ASM as PrevASM
,ASM.KDGID2
,R.ResourceName
,R.ID_ResourceID
,A.ServiceOrderNumber
,CONCAT(EN.TECHVORNAME, ' ' , EN.TECHNACHNAME) as TechName
,A.PrevTech
,EN.TechnicianID
,AAD.ID_ActivityID
,SO.ServiceOrderNumber
,AAD.VisitNumber
,AAD.PlannedDuration
,AAD.ActualDuration
,AAD.PlannedDuration-AAD.ActualDuration as DIFF
,DR.Original_Duration
FROM
[Easy].[ASMTrans] AS ASM
INNER JOIN
[FS_OTBE].[EngPayrollNumbers] AS EN
ON ASM.KDGID2 = EN.KDGID2
INNER JOIN
[OFSA].[ResourceID] AS R
ON EN.TechnicianID = Try_cast(R.ResourceName as int)
INNER JOIN
[OFSDA].[ArchiveActivityDetails] as [AAD]
ON R.[ID_ResourceID] = AAD.ID_ResourceID
INNER JOIN
[OFSA].[ServiceOrderNumber] SO
ON SO.ID_ServiceOrderNumber = AAD.ID_ServiceOrderNumber
LEFT JOIN
[OFSE].[DurationRevision] DR
on DR.ID_ActivityID = AAD.ID_ActivityID
CROSS APPLY
(
SELECT
AD.Date
,AD.ID_CountryCode
,AD.ID_Status
,Activity_TypeID
,AD.ID_ActivityID
,AD.ID_ResourceID
,SO.ServiceOrderNumber
,ASM.ASM
,LAG(EN.TECHVORNAME+ ' '+EN.TECHNACHNAME) OVER (ORDER BY SO.ServiceOrderNumber,AD.ID_ActivityID) as PrevTech
,AD.VisitNumber
,AD.ID_ServiceOrderNumber
,AD.PlannedDuration
,AD.ActualDuration
,ROW_NUMBER() OVER (PARTITION BY AD.ID_ServiceOrderNumber Order by AD.ID_ActivityID,AD.Date) as ROWNUM
FROM
[Easy].[ASMTrans] AS ASM
INNER JOIN
[FS_OTBE].[EngPayrollNumbers] AS EN
ON ASM.KDGID2 = EN.KDGID2
INNER JOIN
[OFSA].[ResourceID] AS R
ON EN.TechnicianID = Try_cast(R.ResourceName as int)
INNER JOIN
[OFSDA].[ArchiveActivityDetails] as [AD]
ON R.[ID_ResourceID] = AD.ID_ResourceID
INNER JOIN
[OFSA].[ServiceOrderNumber] SO
ON SO.ID_ServiceOrderNumber = AD.ID_ServiceOrderNumber
WHERE
AAD.ID_ActivityID = AD.ID_ActivityID
AND
AD.ID_CountryCode = AAD.ID_CountryCode
AND AD.ID_Status = AAD.ID_Status
AND AD.ID_ResourceID = AAD.ID_ResourceID
AND AD.Activity_TypeID = AAD.Activity_TypeID
AND AD.ID_ServiceOrderNumber = AAD.ID_ServiceOrderNumber
AND AD.Date >= '2019-05-01'
) as A
WHERE
ASM.KDGID2
IN (50008323,50008326,50008329,50008332,50008335,50008338,50008341,50008344,50008347,50008350,50008353,50008356,50008359,50008362,50008365)
AND AAD.ID_Status = 1
AND AAD.ID_CountryCode = 7
AND AAD.Activity_TypeID=91
AND
(
AAD.[Date] BETWEEN IIF(#DateFrom < '20190520','20190520',#DateFrom) AND IIF(#DateTo < '20190520','20190520',#DateTo))
AND AAD.ActualDuration > 11
AND
(
(DR.Original_Duration >= 60)
OR
(DR.ID_ActivityID IS NULL AND AAD.PlannedDuration >= 60))
I expect to see the previous Tech and previous Area Sales Manager for the job that was Manually Ammended.
Business Reason: Managers want to see who initially requested for the job to be Manually Ammended. The time requested is being over estimated which is wasting time. To plan better they need to see who requests extra time at a job and try to reduce the time.
I will attach the ArchiveActivityDetail table showing the history of a Repair Order as well as expected results.
Your query results in the cross apply will appear as a table in your query, so you can use top(1) and order by descending to get the first row ordered by what you want (it looks like ActivityId? maybe VisitNumber?).
Simplifying to get at the root of the issue, say you have just one table with ServiceOrderNumber, ID_Activity, ASM, and TECH. To get the previous row for activity 2414073 you would do this:
select top(1) ASM, TECH
from OFSDA.ArchiveActivityDetails as AD
where ID_ServiceOrderNumber = 2370634229 -- same ServiceOrderNumber
and ID_Activity < 2414073 -- previous activities
order by ID_Activity desc -- highest activity less than 2414073
Instead of cross apply, you probably want to use outer apply. This is the same but you will get a row in your main query for the first activity, it will just have nulls for values in your apply. If you want the first row omitted from your results because it doesn't have a previous row, go ahead and use cross apply.
You can just put the above query into the parenthesis in outer apply() and add an alias (Previous). You link to the values for the current row in your main query, use top(1) to get the first row only, and order by ID_Activity descending to get the row with the highest ID_Activity.
select ASM, TECH,
PreviousASM, PreviousTECH
from OFSDA.ArchiveActivityDetails as AD
outer apply (
select top(1) ADInner.ASM as PreviousASM, ADInner.TECH as PreviousTECH
from OFSDA.ArchiveActivityDetails as ADInner
where ADInner.ID_ServiceOrderNumber = AD.ID_ServiceOrderNumber
and ADInner.ID_Activity < AD.ID_Activity
order by ADInnerID_Activity desc
) Previous
where ID_ServiceOrderNumber = 2370634229
I hve to display several cell values into one cell. So I am using this query:
select LISTAGG(fc.DESCRIPTION, ';'||chr(10))WITHIN GROUP (ORDER BY fc.SWITCH_NAME) AS DESCRIP from "ORS".SWITCH_OPERATIONS fc
group by fc.SWITCH_NAME
It is working fine. But when I am merging this with my main(complete) query then I am getting the error as: Error code 1427, SQL state 21000: ORA-01427: single-row subquery returns more than one row
Here is my complete query:
SELECT
TRACK_EVENT.LOCATION,
TRACK_EVENT.ELEMENT_NAME,
(select COUNT(*) from ORS.TRACK_EVENT b where (b.ELEMENT_NAME = sw.SWITCH_NAME)AND (b.ELEMENT_TYPE = 'SWITCH')AND (b.EVENT_TYPE = 'I')AND (b.ELEMENT_STATE = 'NORMAL' OR b.ELEMENT_STATE = 'REVERSE'))as COUNTER,
(select COUNT(*) from ORS.SWITCH_OPERATIONS fc where TRACK_EVENT.ELEMENT_NAME = fc.SWITCH_NAME and fc.NO_CORRESPONDENCE = 1 )as FAIL_COUNT,
(select MAX(cw.COMMAND_TIME) from ORS.SWITCH_OPERATIONS cw where ((TRACK_EVENT.ELEMENT_NAME = cw.SWITCH_NAME) and (cw.NO_CORRESPONDENCE = 1)) group by cw.SWITCH_NAME ) as FAILURE_DATE,
(select LISTAGG(fc.DESCRIPTION, ';'||chr(10))WITHIN GROUP (ORDER BY fc.SWITCH_NAME) AS DESCRIP from "ORS".SWITCH_OPERATIONS fc
group by fc.SWITCH_NAME)
FROM
ORS.SWITCH_OPERATIONS sw,
ORS.TRACK_EVENT TRACK_EVENT
WHERE
sw.SEQUENCE_ID = TRACK_EVENT.SEQUENCE_ID
Not only are subqueries in the SELECT list required to return exactly one row (or any time they're used for a singular comparison, like <, =, etc), but their use in that context tends to make the database execute them RBAR - Row-by-agonizing-row. That is, they're slower and consume more resources than they should.
Generally, unless the result set outside the subquery contains only a few rows, you want to construct subqueries as part of a table-reference. Ie, something like:
SELECT m.n, m.z, aliasForSomeTable.a, aliasForSomeTabe.bSum
FROM mainTable m
JOIN (SELECT a, SUM(b) AS bSum
FROM someTable
GROUP BY a) aliasForSomeTable
ON aliasForSomeTable.a = m.a
This benefits you in other ways to - it's easier to get multiple columns out of the same table-reference, for example.
Assuming that LISTAGG(...) can be included with other aggregate functions, you can change your query to look like this:
SELECT Track_Event.location, Track_Event.element_name,
Counted_Events.counter,
Failure.fail_count, Failure.failure_date, Failure.descrip
FROM ORS.Track_Event
JOIN ORS.Switch_Operations
ON Switch_Operations.sequence_id = Track_Event.sequence_id
LEFT JOIN (SELECT element_name, COUNT(*) AS counter
FROM ORS.Track_Event
WHERE element_type = 'SWITCH'
AND event_type = 'I'
AND element_state IN ('NORMAL', 'REVERSE')
GROUP BY element_name) Counted_Events
ON Counted_Events.element_name = Switch_Operations.swicth_name
LEFT JOIN (SELECT switch_name,
COUNT(CASE WHEN no_correspondence = 1 THEN '1' END) AS fail_count,
MAX(CASE WHEN no_correspondence = 1 THEN command_time END) AS failure_date,
LISTAGG(description, ';' || CHAR(10)) WITHIN GROUP (ORDER BY command_time) AS descrip
FROM ORS.Switch_Operations
GROUP BY switch_name) Failure
ON Failure.switch_name = Track_Event.element_name
This query was written to (attempt to) preserve the semantics of your original query. I'm not completely sure that's what you actually need but without sample starting data and desired results, I have no way to tell how else to improve this. For instance, I'm a little suspicious of the need of Switch_Operations in the outer query, and the fact that LISTAGG(...) is run over row where no_correspondence <> 1. I did change the ordering of LISTAGG(...), because the original column would not have done anything (because the order way the same as the grouping), so would not have been a stable sort.
Single-row subquery returns more than one row.
This error message is self descriptive.
Returned field can't have multiple values and your subquery returns more than one row.
In your complete query you specify fields to be returned. The last field expects single value from the subquery but gets multiple rows instead.
I have no clue about the data you're working with but either you have to ensure that subquery returns only one row or you have to redesign the wrapping query (possibly using joins when appropriate).