I have Azure SQL database. There are 100 rows in table.
I have columns CustomerName, SalesAmount, SalesTime in CustomerSales table.
'Nissan','20000','2021-11-19 17:00:27.9866667'
'Nissan','25000','2021-11-02 17:00:27.9866667'
'Tesla' ,'60000','2021-11-01 17:00:27.9866667'
...
I would like make select query which returns single row of latest like
'Nissan','20000','2021-11-19 17:00:27.9866667'
How?
Order the rows in descending order by sales time, and then get first returned row only.
For example:
select top 1 *
from t
order by SalesTime DESC
Related
Failed finding a solution to my problem, would love your help.
~~ Post has been edited to have only one question ~~-
Group by one query while selecting multiple columns.
In MySQL you can simply group by whatever you want, and it will still select all of them, so if for example I wanted to select the newest 100 transactions, grouped by Email (only get the last transaction of a single email)
In MySQL I would do that:
SELECT * FROM db.transactionlog
group by Email
order by TransactionLogId desc
LIMIT 100;
In SQL Server its not possible, googling a bit suggested to specify each column that I want to have with an aggregate as a hack, that couldn't cause a mix of values (mixing columns between the grouped rows)?
For example:
SELECT TOP(100)
Email,
MAX(ResultCode) as 'ResultCode',
MAX(Amount) as 'Amount',
MAX(TransactionLogId) as 'TransactionLogId'
FROM [db].[dbo].[transactionlog]
group by Email
order by TransactionLogId desc
TransactionLogId is the primarykey which is identity , ordering by it to achieve the last inserted.
Just want to know that the ResultCode and Amount that I'll get doing such query will be of the last inserted row, and not the highest of the grouped rows or w/e.
~Edit~
Sample data -
row1:
Email : test#email.com
ResultCode : 100
Amount : 27
TransactionLogId : 1
row2:
Email: test#email.com
ResultCode:50
Amount: 10
TransactionLogId: 2
Using the sample data above, my goal is to get the row details of
TransactionLogId = 2.
but what actual happens is that I get a mixed values of the two, as I do get transactionLogId = 2, but the resultcode and amount of the first row.
How do I avoid that?
Thanks.
You should first find out which is the latest transaction log by each email, then join back against the same table to retrieve the full record:
;WITH MaxTransactionByEmail AS
(
SELECT
Email,
MAX(TransactionLogId) as LatestTransactionLogId
FROM
[db].[dbo].[transactionlog]
group by
Email
)
SELECT
T.*
FROM
[db].[dbo].[transactionlog] AS T
INNER JOIN MaxTransactionByEmail AS M ON T.TransactionLogId = M.LatestTransactionLogId
You are currently getting mixed results because your aggregate functions like MAX() is considering all rows that correspond to a particular value of Email. So the MAX() value for the Amount column between values 10 and 27 is 27, even if the transaction log id is lower.
Another solution is using a ROW_NUMBER() window function to get a row-ranking by each Email, then just picking the first row:
;WITH TransactionsRanking AS
(
SELECT
T.*,
MostRecentTransactionLogRanking = ROW_NUMBER() OVER (
PARTITION BY
T.Email -- Start a different ranking for each different value of Email
ORDER BY
T.TransactionLogId DESC) -- Order the rows by the TransactionLogID descending
FROM
[db].[dbo].[transactionlog] AS T
)
SELECT
T.*
FROM
TransactionsRanking AS T
WHERE
T.MostRecentTransactionLogRanking = 1
I want to distinguish Rows on the basis of two or more columns value of the same table at the same time returns all columns from the table.
Ex: I have this table
DB Table
I want my result to be displayed as: filter on the basis of type and Number only. As in abover table type and Number for first and second Row is same so it should be suppressed in result.
txn item Discrip Category type Number Mode
60 2 Loyalty L 6174 XXXXXXX1390 0
60 4 Visa C 1600 XXXXXXXXXXXX4108 1
I have tried with sub query but yet unsuccessful. Please suggest what to try.
Thanks
You can do what you want with row_number():
select t.*
from (select t.*,
row_number() over (partition by type, number order by item) as seqnum
from t
) t
where seqnum = 1;
I have a table Trial_tb with columns p_id,t_number and rundate.
Sample values:
p_id|t_number|rundate
=====================
111|333 |1/7/2016||
111|333 |1/1/2016||
222|888 |1/8/2016||
222|444 |1/2/2016||
666|888 |1/6/2016||
555|777 |1/5/2016||
pid and tnumber are key columns. I need fetch values such that the result should not have any record in which pid-tnumber combination are duplicated. For example there is duplication for 111|333 and hence not valid. The query should fetch all other than first two records.
I wrote below script but it fetches only the last record. :(
select rundate,p_id,t_number from
(
select rundate,p_id,t_number,
count(p_id) over (partition by p_id) PCnt,
count(t_number) over (partition by t_number) TCnt
from trialtb
)a
where a.PCnt=1 and a.TCnt=1
The having clause is ideal for this job. Having allows you to filter on aggregated records.
-- Finding unique combinations.
SELECT
p_id,
t_number
FROM
trialtb
GROUP BY
p_id,
t_number
HAVING
COUNT(*) = 1
;
This query returns combinations of p_id and t_number that occur only once.
If you want to include rundate you could add MAX(rundate) AS rundate to the select clause. Because you are only looking at unique occurrences the max or min would always be the same.
Do you mean:
select
p_id,t_number
from
trialtb
group by
p_id,t_number
having
count(*) = 1
or do you need the run date too?
select
p_id,t_number,max(rundate)
from
trialtb
group by
p_id,t_number
having
count(*) = 1
Seeing as you are only looking items with one result using max or min should work fine
I would like to see a most concise way to do what is outlined in this SO question: Sum values from multiple rows into one row
that is, combine multiple rows while summing a column.
But how to then delete the duplicates. In other words I have data like this:
Person Value
--------------
1 10
1 20
2 15
And I want to sum the values for any duplicates (on the Person col) into a single row and get rid of the other duplicates on the Person value. So my output would be:
Person Value
-------------
1 30
2 15
And I would like to do this without using a temp table. I think that I'll need to use OVER PARTITION BY but just not sure. Just trying to challenge myself in not doing it the temp table way. Working with SQL Server 2008 R2
Simply put, give me a concise stmt getting from my input to my output in the same table. So if my table name is People if I do a select * from People on it before the operation that I am asking in this question I get the first set above and then when I do a select * from People after the operation, I get the second set of data above.
Not sure why not using Temp table but here's one way to avoid it (tho imho this is an overkill):
UPDATE MyTable SET VALUE = (SELECT SUM(Value) FROM MyTable MT WHERE MT.Person = MyTable.Person);
WITH DUP_TABLE AS
(SELECT ROW_NUMBER()
OVER (PARTITION BY Person ORDER BY Person) As ROW_NO
FROM MyTable)
DELETE FROM DUP_TABLE WHERE ROW_NO > 1;
First query updates every duplicate person to the summary value. Second query removes duplicate persons.
Demo: http://sqlfiddle.com/#!3/db7aa/11
All you're asking for is a simple SUM() aggregate function and a GROUP BY
SELECT Person, SUM(Value)
FROM myTable
GROUP BY Person
The SUM() by itself would sum up the values in a column, but when you add a secondary column and GROUP BY it, SQL will show distinct values from the secondary column and perform the aggregate function by those distinct categories.
Following problem:
I need to get the position of a record in the table. Let's say I have five record in the table:
Name: john doe, ID: 1
Name: jane doe, ID: 2
Name: Frankie Boy, ID: 4
Name: Johnny, ID: 9
Now, "Frankie Boy" is in the third position in the table. But How to get this information from the SQL server? I could count IDs, but they are not reliable, Frankie has the ID 4, but is in the third position because the record with the ID '3' was deleted.
Is there a way? I am aware of ROW_RANK but it would be costly, because I need to select basically the whole set first before I can rank row_rank them.
I am using MS SQL Server 2008 R2.
Tables don't have 'position'. Rows in a table (=set) are identified by their primary key value. Only result rows have 'position' which can be deterministic when a ORDER BY clause is present. Assuming that tables (=sets) have a position will lead only to problems and is the wrong mind set.
You can use row_number() to "label" rows. You've got to specify a way to order the rows:
select row_number() over (order by id) as PositionInTable
, *
from YourTable
If performance is an issue, you could store the position in a new column:
update yt1
set PositionInTable = rn
from YourTable yt1
join (
select row_number() over (order by id) as rn
, id
from YourTable
) yt2
on yt1.id = yt2.id
With an index on PositionInTable, this would be lightning fast. But you would have to update this after each insert on the table.
Tables are [conceptually] without order. Unless you specify ORDER BY in a select statement to order a results set, results may be returned in any order. Repeated executions of the exact same SQL may return the results set in different orders fro each execution.
To get the row number in a particular result set, use the row_number() function:
select row = row_number() over( order by id ) , *
from sysobjects
This will assign a row number to each row in sysobjects as if the table were ordered by id.
A simple way to do this without having to use ROW_NUMBER would be to simply count how many rows in the table have an index less or equal to the selected index, this would give the row number.
SELECT COUNT(*) FROM YourTable WHERE ID <= 4 -- Frankie Boy, Result = 3
This may not be the most efficient way to do it for your particular scenario, but it's a simple way of achieving it.