I need to match scrap records in one table with records indicating the material that was running at the same time on a machine. I have a table with the scrap counts and a table with records showing whenever the material changed on a machine.
I have a working query of which I will include a simplified version below, but it is very slow when applied to a large data set. I would like to try one of Oracle's analytical functions to make it faster, but I can't figure out how. I tried FIRST_VALUE, and ROW_NUMBER in a few different forms, but I couldn't get them right. Looking for any suggestions.
Please let me know if you would like more details.
Following are simplified versions of the tables:
Scrap readings table (~41m rows)
Machine
ScrapReasonCode
ScrapQuantity
ReportTime
Material numbers (~3m rows)
Machine
MaterialNumber
MEASUREMENT_TIMESTAMP
SELECT Scrap.Machine,
Scrap.MaterialNumber,
Scrap.ScrapReasonCode,
Scrap.ScrapQuantity,
Scrap.ReportTime
FROM Scrap, Materials
WHERE Scrap.Machine = Materials.Machine
AND Materials.MEASUREMENT_TIMESTAMP =
(SELECT MAX (M2.MEASUREMENT_TIMESTAMP)
FROM Materials M2
WHERE M2.Materials.Machine = Scrap.Machine
AND M2.MEASUREMENT_TIMESTAMP <= Scrap.ReportTime)
I think this is what you are trying to do. You can use the FIRST_VALUE window function.
SELECT DISTINCT
s.Machine,
s.MaterialNumber,
s.ScrapReasonCode,
s.ScrapQuantity,
s.ReportTime,
FIRST_VALUE(m.MEASUREMENT_TIMESTAMP) OVER(PARTITION BY s.Machine ORDER BY m.MEASUREMENT_TIMESTAMP DESC)
--or you can use the `MAX` window function too.
--MAX(m.MEASUREMENT_TIMESTAMP) OVER(PARTITION BY s.Machine)
FROM Scrap s
JOIN Materials m
WHERE s.Machine = m.Machine AND m.MEASUREMENT_TIMESTAMP <= s.ReportTime
I may be misunderstanding your requirements but I believe the following query should work in terms of implementing using ROW_NUMBER:
SELECT q.*
FROM (
SELECT ROW_NUMBER() OVER (PARTITION BY Scrap.Machine ORDER BY Materials.MEASUREMENT_TIMESTAMP DESC) AS RNO
Scrap.MaterialNumber,
Scrap.ScrapReasonCode,
Scrap.ScrapQuantity,
Scrap.ReportTime
FROM Scrap, Materials
WHERE Scrap.Machine = Materials.Machine
AND Materials.MEASUREMENT_TIMESTAMP <= Scrap.ReportTime
) q
WHERE q.RNO = 1
Edit: if you need the measurement timestamp before (rather than on-or-before) the Scrap ReportTime, you could just change the <= sign to a < sign in the query above.
Related
If have the below query (simplified example of my query, for the purposes of readability):
SELECT make, year, color, count(*)
FROM cars
GROUPY BY make, year, color
ORDER BY 4 DESC;
I want to iterate through the resulting table and produce sub queries for the criteria of each row (examples below). I hope to then use these sub queries to make a single table with samples results (maybe 3 rows) that meet the criteria of each of the rows from the original query results (ex. as there are multiple Jeeps from 2019 in color black).
SELECT * from cars
WHERE make = 'Jeep'
AND year = '2019'
AND color = 'Black';
SELECT * from cars
WHERE make = 'Ford'
AND year = '2018'
AND color = 'Red';
This may seem like an odd or unnecessary request. However, I believe that this is the best approach given the complexity of my actual problem. This is the approach I want to take, as I want a simplified solution that I can come back to and alter for future use and for different variations of queries.
I am currently using ROW_NUMBER() to retrieve a maximum of three rows per group as my approach (below). Although this compiles for me, it has never run to completion because it has a very long runtime. When I go through the process manually (that I hope to automate with this query), the runtime to produce the desired output doesn't take too long (an hour or two). However, when I run this solution it remains running for the entire day and then Oracle stops the process as a result of the database connection timing out. Does anyone have a better approach to this problem, or perhaps a way to make this run more efficiently?
select *
from (
select c.*,
row_number() over(partition by make, year, color order by id) as rn
from cars c
) x
where rn <= 3
NOTE: I am using Oracle SQL Developer
You can get all queries by dynamically create another column like :
SELECT DISTINCT make, year, color,
'SELECT * from cars WHERE make =''' || make ||''' AND year = ''' || year ||''' AND color = ''' || color ||'''' AS SELECT_STATEMENTS
FROM (select *
from (
select c.*,
row_number() over(partition by make, year, color order by id) as rn
from cars c
) x
where rn <= 3)
We have a select statement in production that takes quite a lot of time.
The current query uses row number - window function.
I am trying to rewrite the query and test the same. assuming its orc table fetching aggregate values instead of using row number may help to reduce the execution time, is my assumption
Is something like this possible. Let me know if i am missing anything.
Sorry i am trying to learn, so please bear with my mistakes, if any.
I tried to rewrite the query as mentioned below.
Original query
SELECT
Q.id,
Q.crt_ts,
Q.upd_ts,
Q.exp_ts,
Q.biz_effdt
(
SELECT u.id, u.crt_ts, u.upd_ts, u.exp_ts, u.biz_effdt, ROW_NUMBER() OVER (PARTITION BY u.id ORDER BY u.crt_ts DESC) AS ROW_N
FROM ( SELECT cust_prd.id, cust_prd.crt_ts, cust_prd.upd_ts, cust_prd.exp_ts, cust_prd.biz_effdt FROM MSTR_CORE.cust_prd
WHERE biz_effdt IN ( SELECT MAX(cust_prd.biz_effdt) FROM MSTR_CORE.cust_prd )
) U
)Q WHERE Q.row_n = 1
My attempt:
SELECT cust_prd.id, cust_prd.crt_ts, cust_prd.upd_ts, cust_prd.exp_ts, cust_prd.biz_effdt FROM MSTR_CORE.cust_prd
WHERE biz_effdt IN ( SELECT MAX(cust_prd.biz_effdt) FROM MSTR_CORE.cust_prd )
having cust_prd.crt_ts = max (cust_prd.crt_ts)
I need to write a query in sql and I can't do it correctly. I have a table with 7 columns 1st_num, 2nd_num, 3rd_num, opening_Date, Amount, code, cancel_Flag.
For every 1st_num, 2nd_num, 3rd_num I want to take only the record with the min (cancel_flag), and if there's more then 1 row so take the the newest opening Date.
But when I do group by and choose min and max for the relevant fields, I get a mix of the rows, for example:
1. 12,130,45678,2015-01-01,2005,333,0
2. 12,130,45678,2015-01-09,105,313,0
The result will be
:12,130,45678,2015-01-09,2005,333,0
and that mixes the rows into one
Microsoft sql server 2008 . using ssis by visual studio 2008
my code is :
SELECT
1st_num,
2nd_num,
3rd_num,
MAX(opening_date),
MAX (Amount),
code,
MIN(cancel_flag)
FROM do. tablename
GROUP BY
1st_num,
2nd_num,
3rd_num,
code
HAVING COUNT(*) > 1
How do I take the row with the max date or.min cancel flag as it is without mixing values?
I can't really post my code because of security reasons but I'm sure you can help.
thank you,
Oren
It is very difficult like this to answer, because every DBMS has different syntax.
Anyways, for most dbms this should work. Using row_number() function to rank the rows, and take only the first one by our definition (all your conditions):
SELECT * FROM (
SELECT t.*,
ROW_NUMBER() OVER ( PARTITION BY t.1st_num,t.2nd_num,t.3rd_num order by t.cancel_flag asc,t.opening_date desc) as row_num
FROM YourTable t ) as tableTempName
WHERE row_num = 1
Use NOT EXISTS to return a row as long as no other row with same 1st_num, 2nd_num, 3rd_num has a lower cancel_flag value, or same cancel_flag but a higher opening_Date.
select *
from tablename t1
where not exists (select 1 from tablename t2
where t2.1st_num = t1.1st_num
and t2.2nd_num = t1.2nd_num
and t2.3rd_num = t1.3rd_num
and (t2.cancel_flag < t1.cancel_flag
or (t2.cancel_flag = t1.cancel_flag and
t2.opening_Date > t1.opening_Date)))
Core ANSI SQL-99, expected to work with (almost) any dbms.
I am trying to get the query below to return the TWO lowest PlayedTo results for each PlayerID.
select
x1.PlayerID, x1.RoundID, x1.PlayedTo
from P_7to8Calcs as x1
where
(
select count(*)
from P_7to8Calcs as x2
where x2.PlayerID = x1.PlayerID
and x2.PlayedTo <= x1.PlayedTo
) <3
order by PlayerID, PlayedTo, RoundID;
Unfortunately at the moment it doesn't return a result when there is a tie for one of the lowest scores. A copy of the dataset and code is here http://sqlfiddle.com/#!3/4a9fc/13.
PlayerID 47 has only one result returned as there are two different RoundID's that are tied for the second lowest PlayedTo. For what I am trying to calculate it doesn't matter which of these two it returns as I just need to know what the number is but for reporting I ideally need to know the one with the newest date.
One other slight problem with the query is the time it takes to run. It takes about 2 minutes in Access to run through the 83 records but it will need to run on about 1000 records when the database is fully up and running.
Any help will be much appreciated.
Resolve the tie by adding DatePlayed to your internal sorting (you wanted the one with the newest date anyway):
select
x1.PlayerID, x1.RoundID
, x1.PlayedTo
from P_7to8Calcs as x1
where
(
select count(*)
from P_7to8Calcs as x2
where x2.PlayerID = x1.PlayerID
and (x2.PlayedTo < x1.PlayedTo
or x2.PlayedTo = x1.PlayedTo
and x2.DatePlayed >= x1.DatePlayed
)
) <3
order by PlayerID, PlayedTo, RoundID;
For performance create an index supporting the join condition. Something like:
create index P_7to8Calcs__PlayerID_RoundID on P_7to8Calcs(PlayerId, PlayedTo);
Note: I used your SQLFiddle as I do not have Acess available here.
Edit: In case the index does not improve performance enough, you might want to try the following query using window functions (which avoids nested sub-query). It works in your SQLFiddle but I am not sure if this is supported by Access.
select x1.PlayerID, x1.RoundID, x1.PlayedTo
from (
select PlayerID, RoundID, PlayedTo
, RANK() OVER (PARTITION BY PlayerId ORDER BY PlayedTo, DatePlayed DESC) AS Rank
from P_7to8Calcs
) as x1
where x1.RANK < 3
order by PlayerID, PlayedTo, RoundID;
See OVER clause and Ranking Functions for documentation.
I am trying to wrap my head around this one this morning.
I am trying to show inventory status for parts (for our products) and this query only becomes complex if I try to return all parts.
Let me lay it out:
single table inventoryReport
I have a distinct list of X parts I wish to display, the result of which must be X # of rows (1 row per part showing latest inventory entry).
table is made up of dated entries of inventory changes (so I only need the LATEST date entry per part).
all data contained in this single table, so no joins necessary.
Currently for 1 single part, it is fairly simple and I can accomplish this by doing the following sql (to give you some idea):
SELECT TOP (1) ldDate, ptProdLine, inPart, inSite, inAbc, ptUm, inQtyOh + inQtyNonet AS in_qty_oh, inQtyAvail, inQtyNonet, ldCustConsignQty, inSuppConsignQty
FROM inventoryReport
WHERE (ldPart = 'ABC123')
ORDER BY ldDate DESC
that gets me my TOP 1 row, so simple per part, however I need to show all X (lets say 30 parts). So I need 30 rows, with that result. Of course the simple solution would be to loop X# of sql calls in my code (but it would be costly) and that would suffice, but for this purpose I would love to work this SQL some more to reduce the x# calls back to the db (if not needed) down to just 1 query.
From what I can see here I need to keep track of the latest date per item somehow while looking for my result set.
I would ultimately do a
WHERE ldPart in ('ABC123', 'BFD21', 'AA123', etc)
to limit the parts I need. Hopefully I made my question clear enough. Let me know if you have an idea. I cannot do a DISTINCT as the rows are not the same, the date needs to be the latest, and I need a maximum of X rows.
Thoughts? I'm stuck...
SELECT *
FROM (SELECT i.*,
ROW_NUMBER() OVER(PARTITION BY ldPart ORDER BY ldDate DESC) r
FROM inventoryReport i
WHERE ldPart in ('ABC123', 'BFD21', 'AA123', etc)
)
WHERE r = 1
EDIT: Be sure to test the performance of each solution. As pointed out in this question, the CTE method may outperform using ROW_NUMBER.
;with cteMaxDate as (
select ldPart, max(ldDate) as MaxDate
from inventoryReport
group by ldPart
)
SELECT md.MaxDate, ir.ptProdLine, ir.inPart, ir.inSite, ir.inAbc, ir.ptUm, ir.inQtyOh + ir.inQtyNonet AS in_qty_oh, ir.inQtyAvail, ir.inQtyNonet, ir.ldCustConsignQty, ir.inSuppConsignQty
FROM cteMaxDate md
INNER JOIN inventoryReport ir
on md.ldPart = ir.ldPart
and md.MaxDate = ir.ldDate
You need to join into a Sub-query:
SELECT i.ldPart, x.LastDate, i.inAbc
FROM inventoryReport i
INNER JOIN (Select ldPart, Max(ldDate) As LastDate FROM inventoryReport GROUP BY ldPart) x
on i.ldPart = x.ldPart and i.ldDate = x.LastDate