I have a table of items which change status every few weeks. I want to look at an arbitrary day and figure out how many items were in each status.
For example:
tbl_ItemHistory
ItemID
StatusChangeDate
StatusID
Sample data:
1001, 1/1/2010, 1
1001, 4/5/2010, 2
1001, 6/15/2010, 4
1002, 4/1/2010, 1
1002, 6/1/2010, 3
...
So I need to figure out how many items were in each status for a given day. So on 5/1/2010, there was one item (1001) in status 2 and one item in status 1 (1002).
I want to create a cached table every night that has a row for every item and every day of the year so I can show status changes over time in a chart. I don't know much about SQL. I was thinking about using a for loop, but based on some of the creative answers I've seen on the forum, I doubt that's the right way.
I'm using SQL Server 2008R2
I looked around and I think this is similar to this question: https://stackoverflow.com/questions/11183164/show-data-change-over-time-in-a-chart but that one wasn't answered. Is there a way to do these things?
A coworker showed me a cool way to do it so I thought I would contribute it to the community:
declare #test table (ItemID int, StatusChangeDate datetime, StatusId tinyint);
insert #test values
(1001, '1/1/2010', 1),
(1001, '4/5/2010', 2),
(1001, '6/15/2010', 4),
(1002, '4/2/2010', 1),
(1002, '6/1/2010', 3);
with
itzik1(N) as (
select 1 union all select 1 union all
select 1 union all select 1), --4
itzik2(N) as (select 1 from itzik1 i cross join itzik1), --16
itzik3(N) as (select 1 from itzik2 i cross join itzik2), --256
itzik4(N) as (select 1 from itzik3 i cross join itzik3), --65536 (184 years)
tally(N) as (select row_number() over (order by (select null)) from itzik4)
select ItemID, StatusChangeDate, StatusId from(
select
test.ItemID,
dates.StatusChangeDate,
test.StatusId,
row_number() over (
partition by test.ItemId, dates.StatusChangeDate
order by test.StatusChangeDate desc) as rnbr
from #test test
join (
select dateadd(dd, N,
(select min(StatusChangeDate) from #test) --First possible date
) as StatusChangeDate
from tally) dates
on test.StatusChangeDate <= dates.StatusChangeDate
and dates.StatusChangeDate <= getdate()
) result
where rnbr = 1
Related
I have a table of data for individual audits on inventory. Every audit has a location, an expected value, a variance value, and some other data that aren't really important here.
I am writing a query for Cognos 11 which summarizes a week of these audits. Currently, it rolls everything up into sums by location class. My problem is that there may be multiple audits for individual locations and while I want the variance field to sum the data from all audits regardless of whether it's the first count on that location, I only want the expected value for distinct locations (i.e. only SUM expected value where the location is distinct).
Below is a simplified version of the query. Is this even possible or will I have to write a separate query in Cognos and make it two reports that will have to be combined after the fact? As you can likely tell, I'm fairly new to SQL and Cognos.
SELECT COALESCE(CASE
WHEN location_class = 'A'
THEN 'Active'
WHEN location_class = 'C'
THEN 'Active'
WHEN location_class IN (
'R'
,'0'
)
THEN 'Reserve'
END, 'Grand Total') "Row Labels"
,SUM(NVL(expected_cost, 0)) "Sum of Expected Cost"
,SUM(NVL(variance_cost, 0)) "Sum of Variance Cost"
,SUM(ABS(NVL(variance_cost, 0))) "Sum of Absolute Cost"
,COUNT(DISTINCT location) "Count of Locations"
,(SUM(NVL(variance_cost, 0)) / SUM(NVL(expected_cost, 0))) "Variance"
FROM audit_table
WHERE audit_datetime <= #prompt('EndDate') # audit_datetime >= #prompt('StartDate') #
GROUP BY ROLLUP(CASE
WHEN location_class = 'A'
THEN 'Active'
WHEN location_class = 'C'
THEN 'Active'
WHEN location_class IN (
'R'
,'0'
)
THEN 'Reserve'
END)
ORDER BY 1 ASC
This is what I'm hoping to end up with:
Thanks for any help!
Have you tried taking a look at the OVER clause in SQL? It allows you to use windowed functions within a result set such that you can get aggregates based on specific conditions. This would probably help since you seem to trying to get a summation of data based on a different grouping within a larger grouping.
For example, let's say we have the below dataset:
group1 group2 val dateadded
----------- ----------- ----------- -----------------------
1 1 1 2020-11-18
1 1 1 2020-11-20
1 2 10 2020-11-18
1 2 10 2020-11-20
2 3 100 2020-11-18
2 3 100 2020-11-20
2 4 1000 2020-11-18
2 4 1000 2020-11-20
Using a single query we can return both the sums of "val" over "group1" as well as the summation of the first (based on datetime) "val" records in "group2":
declare #table table (group1 int, group2 int, val int, dateadded datetime)
insert into #table values (1, 1, 1, getdate())
insert into #table values (1, 1, 1, dateadd(day, 1, getdate()))
insert into #table values (1, 2, 10, getdate())
insert into #table values (1, 2, 10, dateadd(day, 1, getdate()))
insert into #table values (2, 3, 100, getdate())
insert into #table values (2, 3, 100, dateadd(day, 1, getdate()))
insert into #table values (2, 4, 1000, getdate())
insert into #table values (2, 4, 1000, dateadd(day, 1, getdate()))
select t.group1, sum(t.val) as group1_sum, group2_first_val_sum
from #table t
inner join
(
select group1, sum(group2_first_val) as group2_first_val_sum
from
(
select group1, val as group2_first_val, row_number() over (partition by group2 order by dateadded) as rownumber
from #table
) y
where rownumber = 1
group by group1
) x on t.group1 = x.group1
group by t.group1, x.group2_first_val_sum
This returns the below result set:
group1 group1_sum group2_first_val_sum
----------- ----------- --------------------
1 22 11
2 2200 1100
The most inner subquery in the joined table numbers the rows in the data set based on "group2", resulting in the records either having a "1" or a "2" in the "rownum" column since there's only 2 records in each "group2".
The next subquery takes that data and filters out any rows that are not the first (rownum = 1) and sums the "val" data.
The main query gets the sum of "val" in each "group1" from the main table and then joins on the subqueried table to get the "val" sum of only the first records in each "group2".
There are more efficient ways to write this such as moving the summation of the "group1" values to a subquery in the SELECT statement to get rid of one of the nested tabled subqueries, but I wanted to show how to do it without subqueries in the SELECT statement.
Have you tried to put the distinct at the bottom like this ?
(SUM(NVL(variance_cost,0)) / SUM(NVL(expected_cost,0))) "Variance",
COUNT(DISTINCT location) "Count of Locations"
FROM audit_table
I have a table as shown in the screenshot (first two columns) and I need to create a column like the last one. I'm trying to calculate the length of each sequence of consecutive values for each id.
For this, the last column is required. I played around with
row_number() over (partition by id, value)
but did not have much success, since the circled number was (quite predictably) computed as 2 instead of 1.
Please help!
First of all, we need to have a way to defined how the rows are ordered. For example, in your sample data there is not way to be sure that 'first' row (1, 1) will be always displayed before the 'second' row (1,0).
That's why in my sample data I have added an identity column. In your real case, the details can be order by row ID, date column or something else, but you need to ensure the rows can be sorted via unique criteria.
So, the task is pretty simple:
calculate trigger switch - when value is changed
calculate groups
calculate rows
That's it. I have used common table expression and leave all columns in order to be easy for you to understand the logic. You are free to break this in separate statements and remove some of the columns.
DECLARE #DataSource TABLE
(
[RowID] INT IDENTITY(1, 1)
,[ID]INT
,[value] INT
);
INSERT INTO #DataSource ([ID], [value])
VALUES (1, 1)
,(1, 0)
,(1, 0)
,(1, 1)
,(1, 1)
,(1, 1)
--
,(2, 0)
,(2, 1)
,(2, 0)
,(2, 0);
WITH DataSourceWithSwitch AS
(
SELECT *
,IIF(LAG([value]) OVER (PARTITION BY [ID] ORDER BY [RowID]) = [value], 0, 1) AS [Switch]
FROM #DataSource
), DataSourceWithGroup AS
(
SELECT *
,SUM([Switch]) OVER (PARTITION BY [ID] ORDER BY [RowID]) AS [Group]
FROM DataSourceWithSwitch
)
SELECT *
,ROW_NUMBER() OVER (PARTITION BY [ID], [Group] ORDER BY [RowID]) AS [GroupRowID]
FROM DataSourceWithGroup
ORDER BY [RowID];
You want results that are dependent on actual data ordering in the data source. In SQL you operate on relations, sometimes on ordered set of relations rows. Your desired end result is not well-defined in terms of SQL, unless you introduce an additional column in your source table, over which your data is ordered (e.g. auto-increment or some timestamp column).
Note: this answers the original question and doesn't take into account additional timestamp column mentioned in the comment. I'm not updating my answer since there is already an accepted answer.
One way to solve it could be through a recursive CTE:
create table #tmp (i int identity,id int, value int, rn int);
insert into #tmp (id,value) VALUES
(1,1),(1,0),(1,0),(1,1),(1,1),(1,1),
(2,0),(2,1),(2,0),(2,0);
WITH numbered AS (
SELECT i,id,value, 1 seq FROM #tmp WHERE i=1 UNION ALL
SELECT a.i,a.id,a.value, CASE WHEN a.id=b.id AND a.value=b.value THEN b.seq+1 ELSE 1 END
FROM #tmp a INNER JOIN numbered b ON a.i=b.i+1
)
SELECT * FROM numbered -- OPTION (MAXRECURSION 1000)
This will return the following:
i id value seq
1 1 1 1
2 1 0 1
3 1 0 2
4 1 1 1
5 1 1 2
6 1 1 3
7 2 0 1
8 2 1 1
9 2 0 1
10 2 0 2
See my little demo here: https://rextester.com/ZZEIU93657
A prerequisite for the CTE to work is a sequenced table (e. g. a table with an identitycolumn in it) as a source. In my example I introduced the column i for this. As a starting point I need to find the first entry of the source table. In my case this was the entry with i=1.
For a longer source table you might run into a recursion-limit error as the default for MAXRECURSION is 100. In this case you should uncomment the OPTION setting behind my SELECT clause above. You can either set it to a higher value (like shown) or switch it off completely by setting it to 0.
IMHO, this is easier to do with cursor and loop.
may be there is a way to do the job with selfjoin
declare #t table (id int, val int)
insert into #t (id, val)
select 1 as id, 1 as val
union all select 1, 0
union all select 1, 0
union all select 1, 1
union all select 1, 1
union all select 1, 1
;with cte1 (id , val , num ) as
(
select id, val, row_number() over (ORDER BY (SELECT 1)) as num from #t
)
, cte2 (id, val, num, N) as
(
select id, val, num, 1 from cte1 where num = 1
union all
select t1.id, t1.val, t1.num,
case when t1.id=t2.id and t1.val=t2.val then t2.N + 1 else 1 end
from cte1 t1 inner join cte2 t2 on t1.num = t2.num + 1 where t1.num > 1
)
select * from cte2
I have a data set where I'm trying to remove records with the following conditions:
If a practid has multiple records with the same date and at least one record has a reason of "L&B" then I want all the practid's for that date to be removed.
DECLARE t table(practid int, statusdate date, reason varchar(100)
INSERT INTO t VALUES (1, '2018-03-01', 'L&B'),
(1, '2018-03-01', 'NULL'),
(1, '2018-04-01, 'R&D'),
(2, '2018-05-01, 'R&D'),
(2, '2018-05-01, 'R&D'),
(2, '2018-03-15', NULL),
(2, '2018-03-15', 'R&D),
(3, '2018-07-01, 'L&B)
With this data set I would want the following result:
PractId StatusDate Reason
1 2018-04-01 R&D
2 2018-05-01 R&D
2 2018-05-01 R&D
2 2018-03-15 NULL
2 2018-03-15 R&D
I tried solving this with a window function but am getting stuck:
SELECT *, ROW_NUMBER() OVER
(PARTITION BY practid, statusdate, CASE WHEN reason = 'L&B' THEN 0 ELSE 1 END) AS rn
FROM table
From my query I can't figure out how to keep Practid = 2 since I would want to keep all the records.
To continue along your current approach, we can use COUNT as an analytic function. We can count the occurrences of the L&B reason over each practid/statusdate window, and then retain only groups where this reason never occurs.
SELECT practid, statusdate, reason
FROM
(
SELECT *,
COUNT(CASE WHEN reason = 'L&B' THEN 1 END) OVER
(PARTITION BY practid, statusdate) cnt
FROM yourTable
) t
WHERE cnt = 0;
Demo
You can try to use not exists with a subquery.
Select *
from t t1
where not exists (
select 1
from t tt
where tt.reason = 'L&B' and t1.statusdate = tt.statusdate
)
sqlfiddle
Edit: Added another case scenario in the notes and updated the sample attachment.
I am trying to write a sql to get an output attached with this question along with sample data.
There are two table, one with distinct ID's (pk) with their current flag.
another with Active ID (fk to the pk from the first table) and Inactive ID (fk to the pk from the first table)
Final output should return two columns, first column consist of all distinct ID's from the first table and second column should contain Active ID from the 2nd table.
Below is the sql:
IF OBJECT_ID('tempdb..#main') IS NOT NULL DROP TABLE #main;
IF OBJECT_ID('tempdb..#merges') IS NOT NULL DROP TABLE #merges
IF OBJECT_ID('tempdb..#final') IS NOT NULL DROP TABLE #final
SELECT DISTINCT id,
current
INTO #main
FROM tb_ID t1
--get list of all active_id and inactive_id
SELECT DISTINCT active_id,
inactive_id,
Update_dt
INTO #merges
FROM tb_merges
-- Combine where the id from the main table matched to the inactive_id (should return all the rows from #main)
SELECT id,
active_id AS merged_to_id
INTO #final
FROM (SELECT t1.*,
t2.active_id,
Update_dt ,
Row_number()
OVER (
partition BY id, active_id
ORDER BY Update_dt DESC) AS rn
FROM #main t1
LEFT JOIN #merges t2
ON t1.id = t2.inactive_id) t3
WHERE rn = 1
SELECT *
FROM #final
This sql partially works. It doesn't work, where the id was once active then gets inactive.
Please note:
the active ID should return the last most active ID
the ID which doesn't have any active ID should either be null or the ID itself
ID where the current = 0, in those cases active ID should be the ID current in tb_ID
ID's may get interchanged. For example there are two ID's 6 and 7, when 6 is active 7 is inactive and vice versa. the only way to know the most current active state is by the update date
Attached sample might be easy to understand
Looks like I might have to use recursive cte for achieiving the results. Can someone please help?
thank you for your time!
I think you're correct that a recursive CTE looks like a good solution for this. I'm not entirely certain that I've understood exactly what you're asking for, particularly with regard to the update_dt column, just because the data is a little abstract as-is, but I've taken a stab at it, and it does seem to work with your sample data. The comments explain what's going on.
declare #tb_id table (id bigint, [current] bit);
declare #tb_merges table (active_id bigint, inactive_id bigint, update_dt datetime2);
insert #tb_id values
-- Sample data from the question.
(1, 1),
(2, 1),
(3, 1),
(4, 1),
(5, 0),
-- A few additional data to illustrate a deeper search.
(6, 1),
(7, 1),
(8, 1),
(9, 1),
(10, 1);
insert #tb_merges values
-- Sample data from the question.
(3, 1, '2017-01-11T13:09:00'),
(1, 2, '2017-01-11T13:07:00'),
(5, 4, '2013-12-31T14:37:00'),
(4, 5, '2013-01-18T15:43:00'),
-- A few additional data to illustrate a deeper search.
(6, 7, getdate()),
(7, 8, getdate()),
(8, 9, getdate()),
(9, 10, getdate());
if object_id('tempdb..#ValidMerge') is not null
drop table #ValidMerge;
-- Get the subset of merge records whose active_id identifies a "current" id and
-- rank by date so we can consider only the latest merge record for each active_id.
with ValidMergeCTE as
(
select
M.active_id,
M.inactive_id,
[Priority] = row_number() over (partition by M.active_id order by M.update_dt desc)
from
#tb_merges M
inner join #tb_id I on M.active_id = I.id
where
I.[current] = 1
)
select
active_id,
inactive_id
into
#ValidMerge
from
ValidMergeCTE
where
[Priority] = 1;
-- Here's the recursive CTE, which draws on the subset of merges identified above.
with SearchCTE as
(
-- Base case: any record whose active_id is not used as an inactive_id is an endpoint.
select
M.active_id,
M.inactive_id,
Depth = 0
from
#ValidMerge M
where
not exists (select 1 from #ValidMerge M2 where M.active_id = M2.inactive_id)
-- Recursive case: look for records whose active_id matches the inactive_id of a previously
-- identified record.
union all
select
S.active_id,
M.inactive_id,
Depth = S.Depth + 1
from
#ValidMerge M
inner join SearchCTE S on M.active_id = S.inactive_id
)
select
I.id,
S.active_id
from
#tb_id I
left join SearchCTE S on I.id = S.inactive_id;
Results:
id active_id
------------------
1 3
2 3
3 NULL
4 NULL
5 4
6 NULL
7 6
8 6
9 6
10 6
I have a dataset of hospitalisations ('spells') - 1 row per spell. I want to drop any spells recorded within a week after another (there could be multiple) - the rationale being is that they're likely symptomatic of the same underlying cause. Here is some play data:
create table hif_user.rzb_recurse_src (
patid integer not null,
eventdate integer not null,
type smallint not null
);
insert into hif_user.rzb_recurse_src values (1,1,1);
insert into hif_user.rzb_recurse_src values (1,3,2);
insert into hif_user.rzb_recurse_src values (1,5,2);
insert into hif_user.rzb_recurse_src values (1,9,2);
insert into hif_user.rzb_recurse_src values (1,14,2);
insert into hif_user.rzb_recurse_src values (2,1,1);
insert into hif_user.rzb_recurse_src values (2,5,1);
insert into hif_user.rzb_recurse_src values (2,19,2);
Only spells of type 2 - within a week after any other - are to be dropped. Type 1 spells are to remain.
For patient 1, dates 1 & 9 should be kept. For patient 2, all rows should remain.
The issue is with patient 1. Spell date 9 is identified for dropping as it is close to spell date 5; however, as spell date 5 is close to spell date 1 is should be dropped therefore allowing spell date 9 to live...
So, it seems a recursive problem. However, I've not used recursive programming in SQL before and I'm struggling to really picture how to do it. Can anyone help? I should add that I'm using Teradata which has more restrictions than most with recursive SQL (only UNION ALL sets allowed I believe).
It's a cursor logic, check one row after the other if it fits your rules, so recursion is the easiest (maybe the only) way to solve your problem.
To get a decent performance you need a Volatile Table to facilitate this row-by-row processing:
CREATE VOLATILE TABLE vt (patid, eventdate, exac_type, rn, startdate) AS
(
SELECT r.*
,ROW_NUMBER() -- needed to facilitate the join
OVER (PARTITION BY patid ORDER BY eventdate) AS rn
FROM hif_user.rzb_recurse_src AS r
) WITH DATA ON COMMIT PRESERVE ROWS;
WITH RECURSIVE cte (patid, eventdate, exac_type, rn, startdate) AS
(
SELECT vt.*
,eventdate AS startdate
FROM vt
WHERE rn = 1 -- start with the first row
UNION ALL
SELECT vt.*
-- check if type = 1 or more than 7 days from the last eventdate
,CASE WHEN vt.eventdate > cte.startdate + 7
OR vt.exac_type = 1
THEN vt.eventdate -- new start date
ELSE cte.startdate -- keep old date
END
FROM vt JOIN cte
ON vt.patid = cte.patid
AND vt.rn = cte.rn + 1 -- proceed to next row
)
SELECT *
FROM cte
WHERE eventdate - startdate = 0 -- only new start days
order by patid, eventdate
I think the key to solving this is getting the first date more than 7 days from the current date and then doing a recursive subquery:
with rrs as (
select rrs.*,
(select min(rrs2.eventdate)
from hif_user.rzb_recurse_src rrs2
where rrs2.patid = rrs.patid and
rrs2.eventdate > rrs.eventdate + 7
) as eventdate7
from hif_user.rzb_recurse_src rrs
),
recursive cte as (
select patid, min(eventdate) as eventdate, min(eventdate7) as eventdate7
from hif_user.rzb_recurse_src rrs
group by patid
union all
select cte.patid, cte.eventdate7, rrs.eventdate7
from cte join
hif_user.rzb_recurse_src rrs
on rrs.patid = cte.patid and
rrs.eventdate = cte.eventdate7
)
select cte.patid, cte.eventdate
from cte;
If you want additional columns, then join in the original table at the last step.