Such SQL query:
SELECT ROW_NUMBER() OVER (PARTITION BY ID, YEAR order by ID ), ID, YEAR
from table t
give me following query set:
1 1000415591 2012
1 1000415591 2013
2 1000415591 2013
1 1000415591 2014
2 1000415591 2014
How could I update records with ROW_NUMBER() equals to 2? Other fields of this records is identically (select distinct from table where id = 1000415591 gives 3 records when there are 5 without distinct keyword), so I can depend only on ROW_NUMBER() value.
I need solution for Oracle, because I saw something similar for SQL-Server but it won't work with Oracle.
You could use a MERGE statement which is quite verbose and easy to understand.
For example,
MERGE INTO t s
USING
(SELECT ROW_NUMBER() OVER (PARTITION BY ID, YEAR order by ID ) RN,
ID,
YEAR
FROM TABLE t
) u ON (s.id = u.id)
WHEN MATCHED THEN
UPDATE SET YEAR = some_value WHERE u.RN = 2)
/
Note You cannot merge the same column which is used to join in the ON clause.
Try to use ROWID field:
UPDATE T
SET t.year = t.year*1000
WHERE (rowid,2) in (SELECT rowid,
ROW_NUMBER()
OVER (PARTITION BY ID, t.YEAR order by ID )
FROM T)
SQLFiddle demo
If you need to delete range of ROWNUMBERS then :
UPDATE T
SET t.year = t.year*1000
WHERE rowid in ( SELECT rowid FROM
(
SELECT rowid,
ROW_NUMBER()
OVER (PARTITION BY ID, t.YEAR order by ID ) as RN
FROM T
) T2 WHERE RN >=2 AND RN <=10
)
SQLFiddle demo
This is not the update statement but this is how to get the 2 rows you wanted to update:
SELECT *
FROM (
SELECT ROW_NUMBER() OVER (PARTITION BY ID, YEAR order by ID ) as rn, ID, YEAR
from t )
where rn = 2
SQLFIDDLE
When I've posted thq question, I've found that this could be wrong approach. I could modify table and add new fields. So better solution to create one more field IDENTITY and update it with numbers from the new sequence from 1 to total row numbers. Then I could update fields based on this IDENTIY field.
I'll keep this question opened if someone come up with solution based on ROW_NUMBER() analytic function.
update TABLE set NEW_ID = TABLE_SEQ.nextval
where IDENTITY in (
select IDENTITY from (
select row_number() over(PARTITION BY ID, YEAR order by ID) as row_num, t.ID, t."YEAR", t.IDENTITY
from TABLE t
) where row_num > 1
)
Related
I need to select the data of all my customers with the records displayed in the image. But I need to get the most recent record only, for example I need to get the order # E987 for John and E888 for Adam. As you can see from the example, when I do the select statement, I get all the order records.
You don't mention the specific database, so I'll answer with a generic solution.
You can do:
select *
from (
select t.*,
row_number() over(partition by name order by order_date desc) as rn
from t
) x
where rn = 1
You can use analytical function row_number.
Select * from
(Select t.*,
Row_number() over (partition by customer_id order by order_date desc) as rn
From your_table t) t
Where rn = 1
Or you can use not exists as follows:
Select *
From yoir_table t
Where not exists
(Select 1 from your_table tt
Where t.customer_id = tt.custome_id
And tt.order_date > t.order_date)
You can do it with a subquery that finds the last order date.
SELECT t.*
FROM yoir_table t
JOIN (SELECT tt.custome_id,
MAX(tt.order_date) MaxOrderDate
FROM yoir_table tt
GROUP BY tt.custome_id) AS tt
ON t.custome_id = tt.custome_id
AND t.order_date = tt.MaxOrderDate
I have a table which has below values:
If Sum of values = 0 with same ID I want to delete them from the table. So result should look like this:
The code I have:
DELETE FROM tmp_table
WHERE ID in
(SELECT ID
FROM tmp_table WITH(NOLOCK)
GROUP BY ID
HAVING SUM(value) = 0)
Only deletes rows with ID = 2.
UPD: Including additional example:
Rows in yellow needs to be deleted
Your query is working correctly because the only group to total zero is id 2, the others have sub-groups which total zero (such as the first two with id 1) but the total for all those records is -3.
What you're wanting is a much more complex algorithm to do "bin packing" in order to remove the sub groups which sum to zero.
You can do what you want using window functions -- by enumerating the values for each id. Taking your approach using a subquery:
with t as (
select t.*,
row_number() over (partition by id, value order by id) as seqnum
from tmp_table t
)
delete from t
where exists (select 1
from t t2
where t2.id = t.id and t2.value = - t.value and t2.seqnum = t.seqnum
);
You can also do this with a second layer of window functions:
with t as (
select t.*,
row_number() over (partition by id, value order by id) as seqnum
from tmp_table t
),
tt as (
select t.*, count(*) over (partition by id, abs(value), seqnum) as cnt
from t
)
delete from tt
where cnt = 2;
I have following table:
I need to filter out the rows for which start date is latest corresponding to its order id .With reference to given table row no 2 and 3 should be the output.
As row 1 and row 2 has same order id and order date but start date is later than first row. And same goes with row number 3 and 4 hence I need to take out row no 3 . I am trying to write the query in SQL server. Any help is appreciated.Please let me know if you need more details.Apologies for poor English
You can do this easily with a ROW_NUMBER() windowed function:
;With Cte As
(
Select *,
Row_Number() Over (Partition By OrderId Order By StartDate Desc) RN
From YourTable
)
Select *
From Cte
Where RN = 1
But I question the StartDate datatype. It looks like these are being stored as VARCHAR. If that is the case, you need to CONVERT the value to a DATETIME:
;With Cte As
(
Select *,
Row_Number() Over (Partition By OrderId
Order By Convert(DateTime, StartDate) Desc) RN
From YourTable
)
Select *
From Cte
Where RN = 1
Another way using a derived table.
select
t.*
from
YourTable t
inner join
(select OrderId, max(StartDate) dt
from YourTable
group by OrderId) t2 on t2.dt = t.StartDate and t2.OrderId = t.OrderId
I'm trying to select previous years' data for the top-selling products from this year to see how they've done over time.
I currently have something like:
SELECT TOP 10 *
WHERE Table.Year = 2016
ORDER BY Table.Transactions DESC
which gets me the data for the current year, but I'm not sure how to pull data for that same top 10 in previous years, given that this year's top 10 likely differs from previous years' top 10.
I was wondering if there was a way to do something along the lines of:
SELECT *
WHERE Table.Year = 2015
AND (order ID was in Top 10 in 2016)
ORDER BY Table.Transactions DESC
Except clearly I have no idea what to put in place of the bracketed condition.
Any suggestions would be greatly appreciated. Thanks!
do you want this:
SELECT *
From Table
WHERE Table.Year = 2015
AND ID IN (
SELECT TOP 10 ID
FROM Table
WHERE Table.Year = 2016
ORDER BY Table.Transactions DESC
)
ORDER BY Table.Transactions DESC
Use window functions:
select t.*
from (select t.*,
row_number() over (partition by year order by transactions desc) as seqnum
from t
) t
where seqnum <= 10;
Another fun way is to use cross apply:
select t.*
from (select 2015 as yyyy union all select 2016) y cross apply
(select top 10 t.*
from t
where t.year = y.yyyy
order by transactions desc
) t;
Instead of listing out the years explicitly, you can use a subquery (select distinct year from t) y.
Note ID should be some unique value like a PK
SELECT *
FROM YourTable
WHERE YourTable.Year = 2015
AND ID IN
(SELECT TOP 10 ID
WHERE Table.Year = 2016
ORDER BY Table.Transactions DESC)
select *
from (select t.*
,dense_rank () over (partition by t.year order by t.transactions desc) as dr
from t
) t
where t.dr <= 10
order by t.year
,t.dr
;
Here is my query:
SELECT TOP 8 id, rssi1, date
FROM history
WHERE (siteName = 'CCL03412')
ORDER BY id DESC
This the result:
How can I reverse this table based on date (Column2) by using SQL?
You can use the first query to get the matching ids, and use them as part of an IN clause:
SELECT id, rssi1, date
FROM history
WHERE id IN
(
SELECT TOP 8 id
FROM history
WHERE (siteName = 'CCL03412')
ORDER BY id DESC
)
ORDER BY date ASC
You could simply use a sub-query. If you apply a TOP clause the nested ORDER BY is allowed:
SELECT X.* FROM(
SELECT TOP 8 id, Column1, Column2
FROM dbo.History
WHERE (siteName = 'CCL03412')
ORDER BY id DESC) X
ORDER BY Column2
Demo
The SELECT query of a subquery is always enclosed in parentheses. It
cannot include a COMPUTE or FOR BROWSE clause, and may only include an
ORDER BY clause when a TOP clause is also specified.
Subquery Fundamentals
try the below :
select * from (SELECT TOP 8 id, rssi1, date
FROM history
WHERE (siteName = 'CCL03412')
ORDER BY id DESC ) aa order by aa.date DESC
didn't run it, but i think it should go well
WITH cte AS
(
SELECT id, rssi1, date, RANK() OVER (ORDER BY ID DESC) AS Rank
FROM history
WHERE (siteName = 'CCL03412')
)
SELECT id, rssi1, date
FROM cte
WHERE Rank <= 8
ORDER BY Date DESC
I have not run this but i think it will work. Execute and let me know if you face error
select id, rssi1, date from (SELECT TOP 8 id, rssi1, date
FROM history
WHERE (siteName = 'CCL03412')
ORDER BY id DESC) order by date ;