I have a sql table
id item date
A apple 2017-09-17
A banana 2017-08-10
A orange 2017-10-01
B banana 2015-06-17
B apple 2014-06-18
How do I write a sql query, so that for each id I get the two most recent items based on date. ex:
id recent second_recent
a orange apple
b banana apple
You can use row_number() and conditional aggregation:
select id,
max(case when seqnum = 1 then item end) as most_recent,
max(case when seqnum = 2 then item end) as most_recent_but_one,
from (select t.*,
row_number() over (partition by id order by date desc) as seqnum
from t
) t
group by id;
Like said on:
SQL: Group by minimum value in one field while selecting distinct rows
You must use A group By to get min
SELECT mt.*,
FROM MyTable mt INNER JOIN
(
SELECT item AS recent, MIN(date) MinDate, ID
FROM MyTable
GROUP BY ID
) t ON mt.ID = t.ID AND mt.date = t.MinDate
I think you can do the same with a order by to get two value instead of one
You can use Pivot table
SELECT first_column AS <first_column_alias>,
[pivot_value1], [pivot_value2], ... [pivot_value_n]
FROM
(<source_table>) AS <source_table_alias>
PIVOT
(
aggregate_function(<aggregate_column>)
FOR <pivot_column> IN ([pivot_value1], [pivot_value2], ... [pivot_value_n])
) AS <pivot_table_alias>;
Learn More with example here
Example
Related
I want to retrieve TOPIC 1 SCORES with the most recent score (excluding null) (sorted by date) for each detailsID, (there are only detailsID 2 and 3 here, therefore only two results should return)
What about getting rid of Topic 1 Scores in GROUP BYdetailsID,Topic 1 Scores ?
Use a subquery to get the max and then join to it.
SELECT a.detailsID,`Topic 1 Scores`, a.Date
FROM Information.scores AS a
JOIN (SELECT detailsID, MAX(Date) "MaxDate"
FROM Information.scores
WHERE `Topic 1 Scores` IS NOT NULL
GROUP BY detailsID) Maxes
ON a.detailsID = Maxes.detailsID
AND a.Date = Maxes.MaxDate
WHERE `Topic 1 Scores` IS NOT NULL
Assuming SQL Server:
SELECT
ROW_NUMBER() OVER (PARTITION BY detailsID ORDER BY Date DESC) AS RowNumber,
detailsID, Date, Topic 1 Scores
FROM
Information.scores
Try doing
SELECT detailsID,`Topic 1 Scores`, MAX(Date) as "Date" GROUP BY "Date"
How do I query for distinct customers? Here's the table I have..
CustID DATE PRODUCT
=======================
1 Aug-31 Orange
1 Aug-31 Orange
3 Aug-31 Apple
1 Sept-24 Apple
4 Sept-25 Orange
This is what I want.
# of New Customers DATE
========================================
2 Aug-31
1 Sept-25
Thanks!
This is a bit tricky. You want to count the first date a customer appears and then do the aggregation:
select mindate, count(*) as NumNew
from (select CustId, min(Date) as mindate
from table t
group by CustId
) c
group by mindate
You could use a simple common table expression to find the first time a user id is used;
WITH cte AS (
SELECT date, ROW_NUMBER() OVER (PARTITION BY custid ORDER BY date) rn
FROM customers
)
SELECT COUNT(*)[# of New Customers], date FROM cte
WHERE rn=1
GROUP BY date
ORDER BY date
An SQLfiddle to test with.
In the SQL space (specifically T-SQL, SQL Server 2008), given this list of values:
Status Date
------ -----------------------
ACT 2012-01-07 11:51:06.060
ACT 2012-01-07 11:51:07.920
ACT 2012-01-08 04:13:29.140
NOS 2012-01-09 04:29:16.873
ACT 2012-01-21 12:39:37.607 <-- THIS
ACT 2012-01-21 12:40:03.840
ACT 2012-05-02 16:27:17.370
GRAD 2012-05-19 13:30:02.503
GRAD 2013-09-03 22:58:48.750
Generated from this query:
SELECT Status, Date
FROM Account_History
WHERE AccountNumber = '1234'
ORDER BY Date
The status for this particular object started at ACT, then changed to NOS, then back to ACT, then to GRAD.
What is the best way to get the minimum date from the latest "group" of records where Status = 'ACT'?
Here is a query that does this, by identifying the groups where the student statuses are the same and then using simple aggregation:
select top 1 StudentStatus, min(WhenLastChanged) as WhenLastChanged
from (SELECT StudentStatus, WhenLastChanged,
(row_number() over (order by "date") -
row_number() over (partition by studentstatus order by "date)
) as grp
FROM Account_History
WHERE AccountNumber = '1234'
) t
where StudentStatus = 'ACT'
group by StudentStatus, grp
order by WhenLastChanged desc;
The row_number() function assigns sequential numbers within groups of rows based on the date. For your data, the two row_numbers() and their difference is:
Status Date
------ -----------------------
ACT 2012-01-07 11:51:06.060 1 1 0
ACT 2012-01-07 11:51:07.920 2 2 0
ACT 2012-01-08 04:13:29.140 3 3 0
NOS 2012-01-09 04:29:16.873 4 1 3
ACT 2012-01-21 12:39:37.607 5 4 1
ACT 2012-01-21 12:40:03.840 6 5 1
ACT 2012-05-02 16:27:17.370 7 6 1
GRAD 2012-05-19 13:30:02.503 8 1 7
GRAD 2013-09-03 22:58:48.750 9 2 7
Notice the last row is constant for rows that have the same status.
The aggregation brings these together and chooses the latest (top 1 . . . order by date desc) of the first dates (min(date)).
EDIT:
The query is easy to tweak for multiple account numbers. I probably should have written that way to begin with, except the final selection is trickier. The results from this has the date for each status and account:
select StudentStatus, min(WhenLastChanged) as WhenLastChanged
from (SELECT StudentStatus, WhenLastChanged, AccountNumber
(row_number() over (partition by AccountNumber order by WhenLastChanged) -
row_number() over (partition by AccountNumber, studentstatus order by WhenLastChanged)
) as grp
FROM Account_History
) t
where StudentStatus = 'ACT'
group by AccountNumber, StudentStatus, grp
order by WhenLastChanged desc;
But you can't get the last one per account quite so easily. Another level of subqueries:
select AccountNumber, StudentStatus, WhenLastChanged
from (select AccountNumber, StudentStatus, min(WhenLastChanged) as WhenLastChanged,
row_number() over (partition by AccountNumber, StudentStatus order by min(WhenLastChanged) desc
) as seqnum
from (SELECT AccountNumber, StudentStatus, WhenLastChanged,
(row_number() over (partition by AccountNumber order by WhenLastChanged) -
row_number() over (partition by AccountNumber, studentstatus order by WhenLastChanged)
) as grp
FROM Account_History
) t
where StudentStatus = 'ACT'
group by AccountNumber, StudentStatus, grp
) t
where seqnum = 1;
This uses aggregation along with the window function row_number(). This is assigning sequential numbers to the groups (after aggregation), with the last date for each account getting a value of 1 (order by min(WhenLastChanged) desc). The outermost select then just chooses that row for each account.
SELECT [Status], MIN([Date])
FROM Table_Name
WHERE [Status] = (SELECT [Status]
FROM Table_Name
WHERE [Date] = (SELECT MAX([Date])
FROM Table_Name)
)
GROUP BY [Status]
Try here Sql Fiddle
Hogan: basically, yes. I just want to know the date/time when the
account was last changed to ACT. The records after the point above
marked THIS are just extra.
Instead of just looking for act we can look for first time status changes and select act (and max) from that.
so... every time a status changes:
with rownumb as
(
select *, row_number() OVER (order by date asc) as rn
)
select status, date
from rownumb A
join rownumb B on A.rn = B.rn-1
where a.status != b.status
now finding the max of the act items.
with rownumb as
(
select *, row_number() OVER (order by date asc) as rn
), statuschange as
(
select status, date
from rownumb A
join rownumb B on A.rn = B.rn-1
where a.status != b.status
)
select max(date)
from satuschange
where status='Act'
I have two tables linked by an AUTO_KEY field, from one table I'm retrieving the number (id), from the other I get several statuses by number(id), each status has a date associated to it.
I need to restrict the results only to the maximum/latest date for all numbers(ids) and the corresponding status
SELECT
OPERATION.NUMBER,
STATUS.STATUS,
Max(STATUS.DATE)
FROM
STATUS,
OPERATION
WHERE
OPERATION.AUTO_KEY = STATUS.AUTO_KEY
From here
Number Status Date
-----------------------------
1 A 10/20/13
1 B 10/15/13
2 A 10/10/13
2 AX 10/05/13
2 AD 10/03/13
3 DD 10/03/13
The outcome should be
Number Status Date
-----------------------------
1 A 10/20/13
2 A 10/10/13
3 DD 10/03/13
Thanks in advance
You can use a CTE with ROW_NUMBER() function. Also Please use a Table JOIN instead FROM STATUS, OPERATION
;With CTE AS (
SELECT O.NUMBER, S.STATUS, S.DATE,
ROW_NUMBER() OVER (ORDER BY S.DATE DESC) RN
FROM STATUS S JOIN OPERATION O
ON O.AUTO_KEY = S.AUTO_KEY
)
SELECT NUMBER, STATUS, DATE
FROM CTE
WHERE RN = 1
ORDER BY NUMBER
SELECT OPERATION.CNUMBER,
STATUS.STATUS,
STATUS.CDATE
FROM STATUS,
OPERATION
WHERE OPERATION.AUTO_KEY = STATUS.AUTO_KEY
AND STATUS.CDATE = (
SELECT MAX(STATUS.CDATE) MAX_DATE
FROM STATUS,
OPERATION
WHERE OPERATION.AUTO_KEY = STATUS.AUTO_KEY
GROUP BY OPERATION.CNUMBER )
I did search around and I found this
SQL selecting rows by most recent date with two unique columns
Which is so close to what I want but I can't seem to make it work.
I get an error Column 'ID' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.
I want the newest row by date for each Distinct Name
Select ID,Name,Price,Date
From table
Group By Name
Order By Date ASC
Here is an example of what I want
Table
ID
Name
Price
Date
0
A
10
2012-05-03
1
B
9
2012-05-02
2
A
8
2012-05-04
3
C
10
2012-05-03
4
B
8
2012-05-01
desired result
ID
Name
Price
Date
2
A
8
2012-05-04
3
C
10
2012-05-03
1
B
9
2012-05-02
I am using Microsoft SQL Server 2008
Select ID,Name, Price,Date
From temp t1
where date = (select max(date) from temp where t1.name =temp.name)
order by date desc
Here is a SQL Fiddle with a demo of the above
Or as Conrad points out you can use an INNER JOIN (another SQL Fiddle with a demo) :
SELECT t1.ID, t1.Name, t1.Price, t1.Date
FROM temp t1
INNER JOIN
(
SELECT Max(date) date, name
FROM temp
GROUP BY name
) AS t2
ON t1.name = t2.name
AND t1.date = t2.date
ORDER BY date DESC
There a couple ways to do this. This one uses ROW_NUMBER. Just partition by Name and then order by what you want to put the values you want in the first position.
WITH cte
AS (SELECT Row_number() OVER (partition BY NAME ORDER BY date DESC) RN,
id,
name,
price,
date
FROM table1)
SELECT id,
name,
price,
date
FROM cte
WHERE rn = 1
DEMO
Note you should probably add ID (partition BY NAME ORDER BY date DESC, ID DESC) in your actual query as a tie-breaker for date
select * from (
Select
ID, Name, Price, Date,
Rank() over (partition by Name order by Date) RankOrder
From table
) T
where RankOrder = 1
I have found another memory efficient way (but probably crude way)that has worked for me in postgress. Order the query by the date desc, then select the first record of each distinct field.
SELECT distinct on (Name) ID, Price, Date from
table
order by Date desc
Use Distinct instead of Group By
Select Distinct ID,Name,Price,Date
From table
Order By Date ASC
http://technet.microsoft.com/en-us/library/ms187831.aspx