For example:
Name Date
A 2018-06-02
B 2018-06-03
B 2018-06-01
C 2018-06-01
What is the best way to get:
B 2018-06-03
B 2018-06-01
A 2018-06-02
C 2018-06-01
Sort order is first by Order by Date DESC, but then should follow by all the records for that Name
Try forcing the max date by each name.
IF OBJECT_ID('tempdb..#Data') IS NOT NULL
DROP TABLE #Data
CREATE TABLE #Data (
Name VARCHAR(10),
Date DATE)
INSERT INTO #Data (
Name,
Date)
VALUES
('A', '2018-06-02'),
('B', '2018-06-03'),
('B', '2018-06-01'),
('C', '2018-06-01')
SELECT
D.Name,
D.Date
FROM
#Data AS D
ORDER BY
MAX(D.Date) OVER (PARTITION BY D.Name ORDER BY D.Date DESC) DESC,
D.Date DESC,
D.Name
Use window function :
order by count(*) over (partition by name) desc, [date] desc, name
For based on date use max() function instead
order by max([date]) over (partition by name) desc, [date] desc, name
This should get you what you want:
WITH VTE AS(
SELECT [name],
CONVERT(date,[date]) AS [date] --that isn't confusing
FROM (VALUES ('A','20180602'),('B','20180603'),('B','20180601'),('C','20180601')) V([Name],[date])),
MaxDate AS (
SELECT *,
MAX([date]) OVER (PARTITION BY [name]) AS MaxDate
FROM VTE)
SELECT [name],[date]
FROM MaxDate
ORDER BY MaxDate DESC,
[date] DESC,
[name] ASC;
EDIT
I recommend you use ExLo's answer. What I posted was headed in the right direction with window functionality but his seems to match exactly what you need.
You should post expected results and possibly more test data to get a better answer.
Without testing I believe this will set you down a good path.
You can use Dense_Rank () Over (Order By Date Desc) As DateRank and Row_Number() Over (Partition By Name Order By Date Desc) As NameDateOrder
If the above is a subquery or cte you can select from that and order by DateRank, NameDateOrder
Use row_number:
declare #t as table ([Name] char(1), [Date] date)
insert into #t values
('A', '2018-06-02')
, ('B', '2018-06-03')
, ('B', '2018-06-01')
, ('C', '2018-06-01')
Select t.*, row_number() over (order by md desc) as r
from
(
select [Name], max([date]) md
from #t
group by [Name]
) x
inner join #t t on t.[Name] = x.[Name]
Related
I am trying to solve a "gaps and islands" by date issue I'm facing (kudos to Gordon Linoff helping me identify this issue). I want to group the below table by person, office and job while respecting order by person,from_date. consider the table below:
declare #temp table(person varchar(25),office varchar(25),job varchar(25),from_date date,to_date date)
insert into #temp values ('jon','ny','programmer','1/1/2020','1/3/2020');
insert into #temp values ('jon','ny','programmer','1/4/2020','1/5/2020');
insert into #temp values ('jon','dc','programmer','1/6/2020','1/7/2020');
insert into #temp values ('jon','ny','programmer','1/8/2020','1/9/2020');
insert into #temp values ('lou','ny','programmer','1/1/2020','1/3/2020');
insert into #temp values ('lou','ny','programmer','1/4/2020','1/5/2020');
insert into #temp values ('lou','dc','programmer','1/6/2020','1/7/2020');
insert into #temp values ('lou','ny','programmer','1/8/2020','1/9/2020');
the intended output is
This is a type of gaps-and-islands problem. If there are no gaps in the dates, the simplest solution is the difference of row numbers:
select person, office, job, min(from_date), max(to_date)
from (select t.*,
row_number() over (partition by person, office, job order by from_date) as seqnum,
row_number() over (partition by person, office order by from_date) as seqnum_2
from t
) t
group by person, office, job, (seqnum - seqnum_2)
This is a general solution:
WITH preceders_and_followers AS (
SELECT
b.person,
b.office,
b.job,
b.from_date,
b.to_date,
CASE
WHEN EXISTS (
SELECT
c.*
FROM
ora$ptt_tmp c
WHERE
b.person = c.person
AND b.office = c.office
AND b.job = c.job
AND ( b.from_date - 1 BETWEEN c.from_date AND c.to_date )
) THEN
1
END AS has_preceder,
CASE
WHEN EXISTS (
SELECT
c.*
FROM
ora$ptt_tmp c
WHERE
b.person = c.person
AND b.office = c.office
AND b.job = c.job
AND ( b.to_date + 1 BETWEEN c.from_date AND c.to_date )
) THEN
1
END AS has_follower
FROM
ora$ptt_tmp b
ORDER BY
1,
2,
3
)
SELECT DISTINCT
pf1.person,
pf1.office,
pf1.job,
pf1.from_date,
(
SELECT
MIN(pf2.to_date)
FROM
preceders_and_followers pf2
WHERE
pf1.person = pf2.person
AND pf1.office = pf2.office
AND pf1.job = pf2.job
AND pf2.to_date >= pf1.from_date
AND has_follower IS NULL
) to_date
FROM
preceders_and_followers pf1
WHERE
pf1.has_preceder IS NULL
ORDER BY
1,
4,
2,
3;
I have a MyTable with this values (columns Id and MyDate)
10 2019-01-01
10 2018-01-01
25 2020-01-01
25 2005-01-01
I'd like keep record based on the most recent date, the result should be
10 2019-01-01
25 2020-01-01
Do you have an idea ?
Thanks,
You can try this using ROW_NUMBER (Transact-SQL)
Create table MyTable (Id int, DtDate Date)
insert into MyTable Values
(10, '2019-01-01'),
(10, '2018-01-01'),
(25, '2020-01-01'),
(25, '2005-01-01')
select * from (
select id
, dtDate
, ROW_NUMBER() OVER(Partition By Id ORDER BY DtDate DESC) AS RowNo
from MyTable
)a where RowNo = 1
Live db<>fiddle demo.
Try this:
select t.* from (
select *,row_number() over (partition by ID order by date desc) as RN from Table ) t
where rn=1
select id, max(myDate)
from myTable
group by id
Try this:
select Id , MyDate
from (select m.*,
row_number() over (partition by Id order by MyDate desc) as rowNum
from MyTable m
) t
where rowNum = 1
Often, the faster method (with the right indexing) is:
select t.*
from t
where t.mydate = (select max(t2.mydate) as t t2 where t2.id = t.id);
The best index is on (id, mydate).
Note: For a small amount of data, the approach doesn't make much difference.
I have this table for testing:
CREATE TABLE #ExchRates
(
[TimeId] int,
[CurrencyId] INT,
[ExchRate] DECIMAL(30,6)
)
INSERT INTO #ExchRates ([TimeId], [CurrencyId], [ExchRate])
VALUES
(
2017030500,
3,
6.142911
),
(
2017030600,
3,
6.152911
),
(
2017030700,
3,
NULL
),
(
2017030800,
3,
5.5
)
;
I want to insert values from this table in other table for one particular day(TimeId BETWEEN GETUTCDATE()-1 AND GETUTCDATE). Problem is when ExchRate is not set (NULL in table #ExchRate). In that case I want to use last known ExchRate for that currency. How can I solve this problem?
Try this-
SELECT * FROM(
SELECT *, ROW_NUMBER() OVER (ORDER BY TimeID DESC) RN
FROM #ExchRates
WHERE ExchRate IS NOT NULL
) A WHERE RN = 1
If you have more than one currency in the table, you can do this following -
SELECT * FROM(
SELECT *, ROW_NUMBER() OVER (PARTITION BY CurrencyId ORDER BY TimeID DESC) RN
FROM #ExchRates
WHERE ExchRate IS NOT NULL
) A WHERE RN = 1
for the case of null you can use row_number() for getting the last value
select * from (select *,row_number() over(partition by CurrencyId order by TimeId desc) rn
from #ExchRates
) a where a.rn=1
Here's your query.
insert into Table2 ([TimeId], [CurrencyId], [ExchRate])
select ([TimeId], [CurrencyId], [ExchRate]),
isnull([ExchRate], (select top 1 [ExchRate] from #ExchRates order by [TimeId] desc)) from #ExchRates
Use ROW_NUMBER() to get the last record you want :
WITH CTE AS (
SELECT *,ROW_NUMBER() OVER (PARTITION BY CurrencyId ORDER BY TimeId DESC) rn
FROM #ExchRates )
SELECT
*
FROM CTE
WHERE rn = 1;
first table is my input and expecting output like second table with out using left join.
this is the table data
declare #table table
(customer_id int,
indicator bit,
salary numeric(22,6)
,netresult numeric(22,6))
INSERT INTO #table (
customer_id
,indicator
,salary
)
VALUES
(1,1,2000),
(1,1,3000),
(2,1,1000),
(1,0,500),
(1,1,5000),
(2,1,2000),
(2,0,100)
select * from #table order by customer_id,indicator desc
I tried in below method it works. Is there any better alternative?
SELECT a.customer_id
,a.indicator
,a.salary
,netresult=p_salary-(2*n_salary)
FROM (
SELECT customer_id
,indicator
,salary
,sum(salary) OVER (PARTITION BY customer_id) p_salary
FROM #table
) a
LEFT JOIN (
SELECT customer_id
,indicator
,salary
,sum(salary) OVER (PARTITION BY customer_id) n_salary
FROM #table
WHERE indicator = 0
) b ON a.customer_id = b.customer_id
order by customer_id,indicator desc
Expected Output
I think you want this:
select t.customer_id, t.indicator,
sum(case when indicator = 1 then salary else - salary end) over (partition by customer_id) as netresult
form #table t;
No joins are necessary.
with math
select t.customer_id, t.indicator, t.salary
, sum((( t.indicator * 2) -1) * salary) over (partition by customer_id) as netresult
from #table t;
I have a SQL table which contains audit information:
GroupId AuditDate ID FirstName LastName
1 01/06/2011 123 Michael Jackson
1 01/09/2010 123 M J
1 01/06/2009 123 Mike J
and trying show the differences between the audit records:
GroupId AuditDate ID Attribute From To
1 01/06/2011 123 FirstName M Michael
1 01/06/2011 123 LastName J Jackson
1 01/09/2010 123 FirstName Mike M
1 01/06/2009 123 FirstName NULL Mike
1 01/06/2009 123 LastName NULL J
I am using the following SQL query:
WITH result AS (
SELECT [Current].Id,
[Current].GroupId,
[Current].AuditDate,
[Current].FirstName,
[Current].LastName
Previous.FirstName AS PFirstName,
Previous.LastName AS PLastName,
FROM
(SELECT
*, ROW_NUMBER() OVER(PARTITION BY GroupId ORDER BY AuditDate ASC) AS RowNumber
FROM
AuditTable
WHERE
Id = #ID
) AS [Current]
LEFT JOIN
(SELECT
*, ROW_NUMBER() OVER(PARTITION BY GroupId ORDER BY AuditDate ASC) AS RowNumber
FROM
AuditTable
WHERE
Id = #ID
) AS [Previous]
ON
[Current].RowNumber = [Previous].RowNumber + 1
)
SELECT r.Id,r.GroupId, r.AuditDate
x.Attribute,
x.[From],
x.[To]
FROM result r
CROSS APPLY
(
VALUES
('FirstName', t.FirstName, t.PFirstName),
('LastName', t.LastName, t.PLastName),
) x (Attribute, [To], [From])
where
ISNULL(x.[From],'') <> ISNULL(x.[To],'')
ORDER BY r.AuditDate asc;
Is it possible to merge two select queries to improve the performance?
Try this query
WITH result AS (
SELECT Id,
GroupId,
AuditDate,
FirstName,
LastName,
ROW_NUMBER() OVER(PARTITION BY GroupId ORDER BY AuditDate ASC) AS RowNumber
FROM AuditTable
WHERE Id = #ID
)
SELECT r.Id,r.GroupId, r.AuditDate,
x.Attribute,
x.[From],
x.[To]
FROM result r LEFT JOIN result r2 ON r.RowNumber = r2.RowNumber + 1
CROSS APPLY (
VALUES ('FirstName', r.FirstName, r2.FirstName),
('LastName', r.LastName, r2.LastName)
) x (Attribute, [To], [From])
WHERE ISNULL(x.[From],'') <> ISNULL(x.[To],'')
ORDER BY r.AuditDate ASC;
Demo on SQLFiddle
You can eliminate both subqueries entirely by using lag():
WITH result AS (
SELECT Id,
GroupId,
AuditDate,
FirstName,
LastName,
lag(FirstName) over (PARTITION BY GroupId ORDER BY AuditDate ASC)
AS PFirstName,
lag(LastName) over (PARTITION BY GroupId ORDER BY AuditDate ASC)
AS PLastName
FROM AuditTable
WHERE Id = #ID
)
...
Here is the relevant documentation.
Update: However, this is only available in SQL Server 2012, unfortunately. If you have an earlier version, you will need some sort of self join.
If you can't use lag(), you should at least be able to reduce your code from 3 queries to 2: include the row number in your first select statement, and left join one subquery to it rather than having two subqueries. I'm not sure whether this way or Chris Moutray's way would be faster.
WITH result AS (
SELECT ROW_NUMBER() OVER(PARTITION BY GroupId ORDER BY AuditDate ASC) AS RowNumber
[Current].Id,
[Current].GroupId,
[Current].AuditDate,
[Current].FirstName,
[Current].LastName
[Previous].FirstName AS PFirstName,
[Previous].LastName AS PLastName,
FROM AuditTable as [Current]
LEFT JOIN
(SELECT
*, ROW_NUMBER() OVER(PARTITION BY GroupId ORDER BY AuditDate ASC) AS RowNumber
FROM
AuditTable
WHERE
Id = #ID
) AS [Previous]
ON
[Current].RowNumber = [Previous].RowNumber + 1
)
You can use LAG in SQL Server 2012. I've used UNION ALL here to unpivot columns into rows.
Depending on how you filter and what your group level is, add/modify the PARTITION BY
DECLARE #foo TABLE (GroupId tinyint, AuditDate date, ID tinyint, FirstName varchar(100), LastName varchar(100));
INSERT #foo VALUES (1, '20110601', 123, 'Michael', 'Jackson'), (1, '20100901', 123, 'M', 'J'), (1, '20090601', 123, 'Mike', 'J');
SELECT
X.GroupId, X.AuditDate, X.ID, X.[From], X.[To]
FROM
(
SELECT
F.GroupId, F.AuditDate, F.ID, 'FirstName' AS Attribute, LAG(F.FirstName) OVER (/*PARTITION BY GroupId, ID*/ ORDER BY AuditDate) AS [From], F.FirstName AS [To]
FROM
#foo F
UNION ALL
SELECT
F.GroupId, F.AuditDate, F.ID, 'LastName' AS Attribute, LAG(F.LastName) OVER (/*PARTITION BY GroupId, ID*/ ORDER BY AuditDate) AS [From], F.LastName AS [To]
FROM
#foo F
) X
WHERE
ISNULL(X.[From], '') <> ISNULL(X.[To], '')
ORDER BY
X.AuditDate DESC, X.Attribute