I can't seem to get this query to work I am pretty sure I have it correct but i keep coming up with errors. I am trying to create a update query to the rows and they way they are sorted by using a where clause to a specific section as well as a join.
Here is my query:
With cte As
(
SELECT Products.Products.PartNumber, Products.Prices.ProductID, Products.Prices.CODE, Products.Prices.Price
ROW_NUMBER() OVER (ORDER BY Price DESC) AS RN
FROM Test
JOIN Products.Prices
ON Products.Products.ID = Products.Prices.ProductID
where partnumber like 'l2%'
Order by Price Desc
)
UPDATE cte SET Number=RN
Thank you.
Instead of updating the row in the table, you could create a VIEW using your ORDER BY query and other queries could check the view instead of the row.
If you want to stick to just your table, you need to check and make sure the ROW ID being set isn't conflicting with any other row. For instance, if you ORDER BY and find row with ID=6 to be the first in the new query, you update it with ID=1. However, row 1 already has ID=1, and that conflicts with your new row ID (Previously row ID=6).
Related
When I join to the right table I am getting way too many duplicates. I am trying to grab the most recent record from the right table however, it does not matter what I try it does not work.
So Far I have tried:
PROC SQL;
CREATE TABLE fs1.sample AS
SELECT A.*,
B.xx1,
max(B.time_s)
FROM lx1.results a left join (Select Distinct C.id, c.per FROM lx2.results c
Where c.id = a.id
and COMPGED(a.txt1, c.txt1,'i') < 100
and c.dt > a.dt
and c.ksv = 37
and datepart(c.lsg) >= '12DEC2020'd ) b
ON a.id = b.id
group by a.id, a.txt1
QUIT;
Unfortunately, I get an error. I also tried using case when exists, but that takes way too long. Essentially I am trying to grab the most recent record from the right table based on time_s. I also want to make sure the record I grab from the right table somewhat matches a.txt1.
Cheers
When you perform a join, you attach all records from the table that match your join conditions.
If the table is indexed appropriately, a subquery could achieve the goal of obtaining the most recent value, however, if the query uses the wrong index, TOP or equivalent functions may return the wrong result.
There are a number of ways to accomplish the task of retrieving the most recent record but they are contingent on a couple of things.
Firstly, you need to be able to identify what the most recent row is, usually by a column called CreatedDate or something similar against the IDs. (You should know what that business logic is, it may be that the table is chronologically entered [as most tables are] and therefore, SubID might be a thing. We're going to assume it is CreatedDate.)
Secondly, you need to rank the rows in terms of the CreatedDate in a descending order so that the newest matching ID is ranked 1.
Finally, you filter your results by 1 to return the newest result, but you could also filter by <= x if you are interested in the top x newest return results per ID.
To use more mathematical language: We are deriving a value from the CreatedDate and ID values and then using that derivative value to sort and filter the data. In this case we are deriving the RowNumber from the CreatedDate in descending order for each ID.
In order to accomplish this, you can use the Windowed Function ROW_NUMBER(),
ROW_NUMBER() OVER (PARTITION BY id ORDER BY CreatedDate DESC) as RankID
This windowed function will return a row value for each ID relative to the CreatedDate in descending order, where the newest created date is equal to 1.
You can then put brackets around the whole query to make it into a table so you will be able to filter the results of that Windowed Function.
SELECT id, txt
(SELECT id, txt
,ROW_NUMBER() OVER (PARTITION BY id ORDER BY CreatedDate DESC) as RankID
FROM SourceTable) A
WHERE RankID = 1
This should achieve your goal of returning the "newest result".
What ever your column is that determines the age of the data relative to the ID, it can be multiple, should be placed within the ORDER BY.
In order to make this query perform faster, you should index your data appropriately, whereby ID is the the first column, and CreatedDate Desc is your next column. This means your system will not have to perform a costly sort every time this runs, but that depends on whether you plan on using this query often and how much overhead it is grabbing.
I have something to fix in my database here it is:
I have a table with duplicate rows like that:
the duplicate columns are IDPatient and IDObjet and you should never have both duplicate and that's why i put Key on both column but it's a bit too late.. so I have to fix this by combining these duplicate row into one without losing data and to put it in order.
Example, as you can see in the picture the column texte_1 contains each one a date 2010-11-25 and 2011-11-04. The date 2010-11-25 come before 2011-11-04 So i have to put 2011-11-04 into the column texte_2 of the first row and looping like that for each data I have in my row and to verify if the date is older or not. If yes, I have to replace the data in the row one with the second row, taking the information we have replace in a temp var and then finding a new column("Texte_X") to insert into the same row my replace data and validating at the same time if it's not older.
I can have multiple duplicate row in my table and I know looping in SQL server is slow, but would really appreciate a good solution to solve this here.
Here's a example of multiple duplicate row
How about a MERGE:
merge mytable as t
using (
select idPatient, idObject, max(texte_1) dt
from mytable
group by idPatient, idObject
) s on t.idPatient = s.idPatient
and t.idObject = s.idObject
and t.texte_1 != s.dt
when matched then delete;
You could use the ROW_NUMBER() function and your ID field to order the duplicates, then PIVOT to de-normalize the records, or self-joins, like:
;with cte as (SELECT *,RN = ROW_NUMBER() OVER(PARTITION BY IDPatient,IDObjet ORDER BY ID)
FROM YourTable
)
SELECT a.IDPatient,a.IDObjet,a.Texte_1, b.Texte_1 as Texte_2, c.Texte_1 AS Texte_3
FROM cte a
LEFT JOIN cte b
ON a.IDPatient = b.IDPatient
AND a.IDObjet = b.IDObjet
AND b.RN = 2
LEFT JOIN cte c
ON a.IDPatient = c.IDPatient
AND a.IDObjet = c.IDObjet
AND c.RN = 3
WHERE a.RN = 1
This assumes the ID order is sufficient, you could change it to your date field if needed. Since you ultimately want to remove the duplicate lines, you could either run this query into a new table, or after you use this as the basis of your update you can then DELETE records from the cte above where RN > 1
Personally, I would avoid the de-normalized Texte_1-10 structure, and add a new field that's the equivalent of the RN field as part of the key.
I tried to do an UPDATE statement with a random row from another table. I know this question has been asked before (here), but it doesn't seem to work for me.
I should update each row with a different value from the other table. In my case it only gets one random row from a table and puts that in every row.
UPDATE dbo.TABLE_CHARGE
SET COLRW_STREET =
(SELECT TOP 1 COLRW_STREET FROM CHIEF_PreProduction.dbo.TABLE_FAKESTREET
ORDER BY ABS(CHECKSUM(NewId())%250))
Thanks in advance!
I took a liberty to assume that you have ID field in your TABLE_CHARGE table. This is probably not the most efficient way, but seems to work:
WITH random_values as
(
SELECT t.id, t.COLRW_STREET, t.random_street FROM (
SELECT c.id, c.COLRW_STREET,
f.COLRW_STREET as random_street, ROW_NUMBER() OVER (partition by c.id ORDER BY ABS(CHECKSUM(NewId())%250)) rn
FROM table_charge c, TABLE_FAKESTREET f) t
WHERE t.rn = 1
)
UPDATE random_values SET COLRW_STREET = random_street;
SQL Fiddle demo
Your original code did not work because when yo do ... SET x = (SELECT TOP 1 ..) database does OUTER JOIN of your target table with one TOP row, which means that one single row is applied to all rows in your target table. Hence you have same value in all rows.
Following query demonstrates what is happening in the UPDATE:
SELECT * FROM
TABLE_CHARGE tc,
(SELECT TOP 1 COLRW_STREET as random_street FROM TABLE_FAKESTREET
ORDER BY ABS(CHECKSUM(NewId())%250)) t
My solution gets all fake records ordered randomly for each record in target table and only selects the first one per ID.
I realize my title probably doesnt explain my situation very well, but I honestly have no idea how to word this.
I am using SQL to access a DB2 database.
Using my screenshot image 1 below as a reference:
column 1 has three instances of "U11124", with three different descriptions (column 2)
I would like this query to return the first instance of "U11124" and its description, but then also unique records for the other rows. image 2 shows my desired result.
image 1
image 2
----- EDIT ----
to answer some of the questions / posts:
technically, it does not need to be the first , just any single one of those records. the problem is that we have three descriptions, and only one needs to be shown, i am now told it does not matter which one.
SELECT STVNST, MAX(STDESC) FROM MY_TABLE GROUP BY STVNST;
In SQL Server:
select stvnst, stdesc
from (
select
stvnst, stdesc
row_number() over (order by stdesc partition by stvnst) row
from table
) a
where row = 1
This method has an advantage over a simple group by, in that it will also work when there's more than two columns in the table.
SELECT STVNST,FIRST(STDESC) from table group by STVNST ORDER BY what_you_want_first
All you need to do is use GROUP BY.
You say you want the first instance of the STDESC column? Well you can't guarntee the order of the rows without another column, however if you want to order by the highest ordered value the following will suffice:
SELECT STVNST, MAX(STDESC) FROM MY_TABLE GROUP BY STVNST;
I am trying to update a table in my database with another row from another table. I have two parameters one being the ID and another being the row number (as you can select which row you want from the GUI)
this part of the code works fine, this returns one column of a single row.
(SELECT txtPageContent
FROM (select *, Row_Number() OVER (ORDER BY ArchiveDate asc) as rowid
from ARC_Content Where ContentID = #ContentID) as test
Where rowid = #rowID)
its just when i try to add the update/set it won't work. I am probably missing something
UPDATE TBL_Content
Set TBL_Content.txtPageContent = (select txtPageContent
FROM (select *, Row_Number() OVER (ORDER BY ArchiveDate asc) as rowid
from ARC_Content Where ContentID = #ContentID) as test
Where rowid = #rowID)
Thanks for the help! (i have tried top 1 with no avail)
I see a few issues with your update. First, I don't see any joining or selection criteria for the table that you're updating. That means that every row in the table will be updated with this new value. Is that really what you want?
Second, the row number between what is on the GUI and what you get back in the database may not match. Even if you reproduce the query used to create your list in the GUI (which is dangerous anyway, since it involves keeping the update and the select code always in sync), it's possible that someone could insert or delete or update a row between the time that you fill your list box and send that row number to the server for the update. It's MUCH better to use PKs (probably IDs in your case) to determine which row to use for updating.
That said, I think that the following will work for you (untested):
;WITH cte AS (
SELECT
txtPageContent,
ROW_NUMBER() OVER (ORDER BY ArchiveDate ASC) AS rowid
FROM
ARC_Content
WHERE
ContentID = #ContentID)
UPDATE
TC
SET
txtPageContent = cte.txtPageContent
FROM
TBL_Content TC
INNER JOIN cte ON
rowid = #rowID