how to not pick 3rd row in select Query - sql-server

i have a table (screenshot attached).when the Table has 3 or more records i don't want it it to pick 3rd row
SQL query:
SELECT POA.PurchaseOrder_AuthID, POA.Authorised,wc.Name ,POA.DateAuthorised,POA.DelayEscalationSentAt,AuthorisingContactID
FROM dbo.wsm_PurchaseOrder_Auth AS POA
INNER JOIN wsm_Contact AS WC ON POA.AuthorisingContactID=wc.ContactID
WHERE POA.PONumber = 'PO3841905_51_200908' order by POA.PurchaseOrder_AuthID
ASC
i can't use Group by as i need all the rows without aggregate function \
authorizing contact id can be different in 2nd and 3rd row (currently showing same in table)

not wanting to pick the 3rd row using ROW_NUMBER window function
select * from
(
select field1,
row_number() over(order by purchaseorder_authid) rn
from table
) x
where x.rn <> 3

this question answered in Previous post but
for sql server after 2012 use this Code:
SELECT *
FROM Table
ORDER BY OrdClm ASC
OFFSET 2 ROWS
FETCH NEXT 1 ROWS ONLY
and Previous version:
SELECT *
FROM (SELECT ROW_NUMBER() OVER(ORDER BY OrdClm ) RowNr, * FROM Table ) t
WHERE RowNr=3

Related

How to get the most recent row in a temporal tables history

I have the following query:
SELECT *
FROM dbo.mytable FOR system_time BETWEEN #rowEffFrom AND #rowEffTo t
WHERE t.anothertableid = 1
ORDER BY t.rowefffrom
My table has the following columns relevant to this question:
Id, AnotherTableId (FK), Description, RowEffFrom, RowEffTo
What I have done is get an entry from tblAnotherTable's history matching certain criteria. I then set #rowEffFrom and #rowEffTo as the RowEffFrom and RowEffTo for the retrieved row (top 1).
myTable has a many to one relationship with tblAnotherTable.
I want to retrieve the latest version of all entries between the #rowEffFrom and #rowEffTo, but one per Id.
e.g.
if my query above returns 2 rows, both with Id of 11, then I just want the most recent. If it returns 6 rows with ids 11,12,13 I want 3 rows with the latest of each version.
Nevermind, the answer is:
SELECT *
FROM ( SELECT Row_number() OVER (partition BY id ORDER BY rowefffrom DESC) rownumber,
*
FROM dbo.mytable FOR system_time BETWEEN #rowEffFrom AND #rowEffTo t
WHERE t.anothertableid = 1 ) mt
WHERE mt.rownumber = 1

Strange behavior of TOP in subquery with Order By

I am using SQL Server 2014 and trying to get 10th record and wrote following query.
SELECT TOP 1 *
FROM (SELECT TOP 10 * from Books) AS B
ORDER BY ID DESC;
But it returns me the the last record. I figure out that it is using order by ID DESC from outer query.
Few more tries and its results are as below.
Query 1 Its working as expected.
SELECT *
FROM (SELECT TOP 10 * from Books) AS B
Result
Query 2 Its not working as expected. It should be return records with ID from 10-1.
SELECT *
FROM (SELECT TOP 10 * from Books) AS B
ORDER BY ID DESC;
Result
Query 3 If I'm using ORDER BY inside subquery then it's working as expected.
SELECT *
FROM (SELECT TOP 10 * from Books ORDER BY ID ASC) AS B
ORDER BY ID DESC;
Result
Can anyone tell me what I'm doing wrong. Why it is necessary to use ORDER BY inside subquery?
If in Query 1 getting records from ID between 1-10 then why in Query 2 it returns last 10 records? I have just added ORDER BY DESC which should re-order fetched records from subquery only.?
Also tried on W3School Try it yourself link here with following query and its working properly.
SELECT TOP 1 * FROM (SELECT TOP 10 * from Customers) AS B ORDER BY CustomerId DESC;
There's no sort in the subquery.
Try a CTE-
WITH CteBooks as (
SELECT TOP 10 * FROM Books ORDER BY ID ASC
)
SELECT TOP 1 * FROM CteBooks ORDER BY ID DESC;
What about OFFSET clause :
SELECT CustomerID
FROM Customers
ORDER BY CustomerID ASC
OFFSET 10 ROWS
FETCH NEXT 1 ROWS ONLY
Works on SQL Server 2012 and select the element at offset 10 and take only one row.

unique chat records sql

I have DB which having 5 column as follows:
message_id
user_id_send
user_id_rec
message_date
message_details
Looking for a SQL Serve Query, I want to Filter Results from two columns (user_id_send,user_id_rec)for Given User ID based on following constrains:
Get the Latest Record (filtered on date or message_id)
Only Unique Records (1 - 2 , 2 - 1 are same so only one record will be returned which ever is the latest one)
Ordered by Descending based on message_id
SQL Query
The main purpose of this query is to get records of user_id to find out to whom he has sent messages and from whom he had received messages.
I have also attached the sheet for your reference.
Here is my try
WITH t
AS (SELECT *
FROM messages
WHERE user_id_sender = 1)
SELECT DISTINCT user_id_reciever,
*
FROM t;
WITH h
AS (SELECT *
FROM messages
WHERE user_id_reciever = 1)
SELECT DISTINCT user_id_sender,
*
FROM h;
;WITH tmpMsg AS (
SELECT M2.message_id
,M2.user_id_receiver
,M2.user_id_sender
,M2.message_date
,M2.message_details
,ROW_NUMBER() OVER (PARTITION BY user_id_receiver+user_id_sender ORDER BY message_date DESC) AS 'RowNum'
FROM messages M2
WHERE M2.user_id_receiver = 1
OR M2.user_id_sender = 1
)
SELECT T.message_id
,T.user_id_receiver
,T.user_id_sender
,T.message_date
,T.message_details
FROM tmpMsg T
WHERE RowNum <= 1
The above should fetch you the results you are looking for when you query for a particular user_id (replace the 1 with parameter e.g. #p_user_id). The user_id_receiver+user_id_sender in the PARTITION clause ensure that records with user id combinations such as 1 - 2, 2 - 1 are not selected twice.
Hope this helps.
select * from
(
select ROW_NUMBER() over (order by message_date DESC) as rowno,
* from messages
where user_id_receiver = 1
--order by message_date DESC
) T where T.rowno = 1
UNION ALL
select * from
(
select ROW_NUMBER() over (order by message_date DESC) as rowno,
* from messages
where user_id_sender = 1
-- order by message_date DESC
) T where T.rowno = 1
Explanation: For each group of user_id_sender, it orders internally by message_date desc, and then adds row numbers, and we only want the first one (chronologically last). Then do the same for user_id_receiver, and union the results together to get 1 result set with all the desired rows. You can then add your own order by clause and additional where conditions at the end as required.
Of course, this only works for any 1 user_id at a time (replace =1 with #user_id).
To get a result from all user_id's at once, is a totally different query, so I hope this helps?

How to retrieve 7th row in a table using SQL query

I have a table with some number of records in it say the table is Student and it has a column named total_mark . Now I need to fetch the details of the student who is 7th largest total from the total_mark column . How to perform this operation in SQL SERVER 2008?
First, define what you mean by "7th". 7th in age? 7th in IQ? 7th in height? Whatever.
WITH
RankedStudents AS (
SELECT *, ROW_NUMBER() OVER ( ORDER BY <Whatever> ) AS RowNumber FROM <Schema>.<Object>
)
SELECT *
FROM RankedStudents
WHERE RowNumber = 7 ;
First select the top 7, then reverse the ordering and take just the first row:
SELECT TOP 1 * FROM (
SELECT TOP 7 *
FROM RankedStudents
ORDER BY total_mark desc) x
ORDER BY total_mark
try this
WITH CTE AS(
SELECT total_mark,RANK() OVER (ORDER BY total_mark DESC)AS RANKED FROM SN_DB)
SELECT DISTINCT * FROM CTE WHERE RANKED = 7

How do I select last 5 rows in a table without sorting?

I want to select the last 5 records from a table in SQL Server without arranging the table in ascending or descending order.
This is just about the most bizarre query I've ever written, but I'm pretty sure it gets the "last 5" rows from a table without ordering:
select *
from issues
where issueid not in (
select top (
(select count(*) from issues) - 5
) issueid
from issues
)
Note that this makes use of SQL Server 2005's ability to pass a value into the "top" clause - it doesn't work on SQL Server 2000.
Suppose you have an index on id, this will be lightning fast:
SELECT * FROM [MyTable] WHERE [id] > (SELECT MAX([id]) - 5 FROM [MyTable])
The way your question is phrased makes it sound like you think you have to physically resort the data in the table in order to get it back in the order you want. If so, this is not the case, the ORDER BY clause exists for this purpose. The physical order in which the records are stored remains unchanged when using ORDER BY. The records are sorted in memory (or in temporary disk space) before they are returned.
Note that the order that records get returned is not guaranteed without using an ORDER BY clause. So, while any of the the suggestions here may work, there is no reason to think they will continue to work, nor can you prove that they work in all cases with your current database. This is by design - I am assuming it is to give the database engine the freedom do as it will with the records in order to obtain best performance in the case where there is no explicit order specified.
Assuming you wanted the last 5 records sorted by the field Name in ascending order, you could do something like this, which should work in either SQL 2000 or 2005:
select Name
from (
select top 5 Name
from MyTable
order by Name desc
) a
order by Name asc
You need to count number of rows inside table ( say we have 12 rows )
then subtract 5 rows from them ( we are now in 7 )
select * where index_column > 7
select * from users
where user_id >
( (select COUNT(*) from users) - 5)
you can order them ASC or DESC
But when using this code
select TOP 5 from users order by user_id DESC
it will not be ordered easily.
select * from table limit 5 offset (select count(*) from table) - 5;
Without an order, this is impossible. What defines the "bottom"? The following will select 5 rows according to how they are stored in the database.
SELECT TOP 5 * FROM [TableName]
Well, the "last five rows" are actually the last five rows depending on your clustered index. Your clustered index, by definition, is the way that he rows are ordered. So you really can't get the "last five rows" without some order. You can, however, get the last five rows as it pertains to the clustered index.
SELECT TOP 5 * FROM MyTable
ORDER BY MyCLusteredIndexColumn1, MyCLusteredIndexColumnq, ..., MyCLusteredIndexColumnN DESC
Search 5 records from last records you can use this,
SELECT *
FROM Table Name
WHERE ID <= IDENT_CURRENT('Table Name')
AND ID >= IDENT_CURRENT('Table Name') - 5
If you know how many rows there will be in total you can use the ROW_NUMBER() function.
Here's an examble from MSDN (http://msdn.microsoft.com/en-us/library/ms186734.aspx)
USE AdventureWorks;
GO
WITH OrderedOrders AS
(
SELECT SalesOrderID, OrderDate,
ROW_NUMBER() OVER (ORDER BY OrderDate) AS 'RowNumber'
FROM Sales.SalesOrderHeader
)
SELECT *
FROM OrderedOrders
WHERE RowNumber BETWEEN 50 AND 60;
In SQL Server 2012 you can do this :
Declare #Count1 int ;
Select #Count1 = Count(*)
FROM [Log] AS L
SELECT
*
FROM [Log] AS L
ORDER BY L.id
OFFSET #Count - 5 ROWS
FETCH NEXT 5 ROWS ONLY;
Try this, if you don't have a primary key or identical column:
select [Stu_Id],[Student_Name] ,[City] ,[Registered],
RowNum = row_number() OVER (ORDER BY (SELECT 0))
from student
ORDER BY RowNum desc
You can retrieve them from memory.
So first you get the rows in a DataSet, and then get the last 5 out of the DataSet.
There is a handy trick that works in some databases for ordering in database order,
SELECT * FROM TableName ORDER BY true
Apparently, this can work in conjunction with any of the other suggestions posted here to leave the results in "order they came out of the database" order, which in some databases, is the order they were last modified in.
select *
from table
order by empno(primary key) desc
fetch first 5 rows only
Last 5 rows retrieve in mysql
This query working perfectly
SELECT * FROM (SELECT * FROM recharge ORDER BY sno DESC LIMIT 5)sub ORDER BY sno ASC
or
select sno from(select sno from recharge order by sno desc limit 5) as t where t.sno order by t.sno asc
When number of rows in table is less than 5 the answers of Matt Hamilton and msuvajac is Incorrect.
Because a TOP N rowcount value may not be negative.
A great example can be found Here.
i am using this code:
select * from tweets where placeID = '$placeID' and id > (
(select count(*) from tweets where placeID = '$placeID')-2)
In SQL Server, it does not seem possible without using ordering in the query.
This is what I have used.
SELECT *
FROM
(
SELECT TOP 5 *
FROM [MyTable]
ORDER BY Id DESC /*Primary Key*/
) AS T
ORDER BY T.Id ASC; /*Primary Key*/
DECLARE #MYVAR NVARCHAR(100)
DECLARE #step int
SET #step = 0;
DECLARE MYTESTCURSOR CURSOR
DYNAMIC
FOR
SELECT col FROM [dbo].[table]
OPEN MYTESTCURSOR
FETCH LAST FROM MYTESTCURSOR INTO #MYVAR
print #MYVAR;
WHILE #step < 10
BEGIN
FETCH PRIOR FROM MYTESTCURSOR INTO #MYVAR
print #MYVAR;
SET #step = #step + 1;
END
CLOSE MYTESTCURSOR
DEALLOCATE MYTESTCURSOR
Thanks to #Apps Tawale , Based on his answer, here's a bit of another (my) version,
To select last 5 records without an identity column,
select top 5 *,
RowNum = row_number() OVER (ORDER BY (SELECT 0))
from [dbo].[ViewEmployeeMaster]
ORDER BY RowNum desc
Nevertheless, it has an order by, but on RowNum :)
Note(1): The above query will reverse the order of what we get when we run the main select query.
So to maintain the order, we can slightly go like:
select *, RowNum2 = row_number() OVER (ORDER BY (SELECT 0))
from (
select top 5 *, RowNum = row_number() OVER (ORDER BY (SELECT 0))
from [dbo].[ViewEmployeeMaster]
ORDER BY RowNum desc
) as t1
order by RowNum2 desc
Note(2): Without an identity column, the query takes a bit of time in case of large data
Get the count of that table
select count(*) from TABLE
select top count * from TABLE where 'primary key row' NOT IN (select top (count-5) 'primary key row' from TABLE)
If you do not want to arrange the table in ascending or descending order. Use this.
select * from table limit 5 offset (select count(*) from table) - 5;

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