How to Use Row_Number()

How to use row_number() in SQL Server

This will update only the first employee of that age. May be used as a lottery type logic

create table emp(name varchar(3),Age int, Salary int, IncentiveFlag bit)

insert into emp values('aaa',23,90000,0);
insert into emp values('bbb',22,50000,0);
insert into emp values('ccc',63,60000,0);
insert into emp values('ddd',53,50000,0);
insert into emp values('eee',23,80000,0);
insert into emp values('fff',53,50000,0);
insert into emp values('ggg',53,50000,0);

update A
set IncentiveFlag=1
from 
(
        Select row_number() over (partition by Age order by age ) AS SrNo,* from emp
)A
where A.SrNo=1

SQL: how to use row_number() function to assign the same number for rows with duplicate ids in a repeating format

Try this below script using DENSE_RANK -

SELECT *,
(DENSE_RANK() OVER(ORDER BY PersonId)-1)%3 + 1 AS numberCount
FROM your_table

Row_number function using directly

First, you want dense_rank(), not row_number() if you want the second highest value -- ties might get in the way otherwise.

You can use an arithmetic trick:

SELECT TOP (1) WITH TIES id, salary, depid
FROM emp
ORDER BY ABS(DENSE_RANK() over (PARTITION BY depid ORDER BY salary DESC) - 2)

The "-2" is an arithmetic trick to put the "second" values highest.

That said, I would stick with the subquery because the intent in clearer.

How to use row_number in a where clause

You need a derived table:

select id, blah, them
from (
  select id,
         blah,
         row_number () over (partition by blah, my_id order by datetime) rn,
         theme
  from documents
) x
where theme = 'cats' 
and rn <= 2;

This is basically syntactic sugar and does not cause a performance overhead.

ROW_NUMBER() OVER (PARTITION BY) gives same row numbers

use this : ROW_NUMBER() OVER(ORDER BY code) it is continue sequence and you use partition by it manse it reset every code.

SELECT ROW_NUMBER() OVER (ORDER BY "ItemCode") AS "ID", "ItemCode", "CommitedQty", "JobId", "WarehouseID"
    FROM
        (SELECT "ItemCode", SUM("CommitedQty") AS "CommitedQty","JobId", "WarehouseID"
        FROM "Stock" 
        WHERE "BaseEntry" = 10352
        GROUP BY "ItemCode","JobId", "WarehouseID")

Use ROW_NUMBER() alias in WHERE

Using subquery:

SELECT 
    *
FROM
    (SELECT 
         inv.client_pk, inv.invoice_pk, inv.contract_pk, 
         ROW_NUMBER() OVER (PARTITION BY inv.client_pk ORDER BY inv.client_pk) AS row_number 
     FROM 
         controllr.client as cli 
     LEFT JOIN 
         controllr.invoice as inv ON inv.client_pk = cli.client_pk                              
     WHERE 
         client_status != 3) AS sub
WHERE 
    row_number <= 3;

Using CTE:

WITH cte AS 
(
    SELECT 
        inv.client_pk, inv.invoice_pk, inv.contract_pk, 
        ROW_NUMBER() OVER ( PARTITION BY inv.client_pk ORDER BY inv.client_pk) AS row_number 
    FROM 
        controllr.client as cli 
    LEFT JOIN 
        controllr.invoice as inv ON inv.client_pk = cli.client_pk                              
    WHERE 
        client_status != 3
)
SELECT *
FROM cte
WHERE row_number <= 3;

The reason why you are receiving that error is because the WHERE clause is processed before the SELECT clause. Therefore, the engine is unable to see row_number as a column when trying to process the condition ... row_number <= 3 with your original query.

Also, using CTE has the same performance of using a subquery but it does improve readability.

Use row_number() to take middle row in a set of records

Edit: Updated to use a cte.
Edit2: Updated to use a join rather than a sub-select to handle multiple castingIds

Since ROW_NUMBER() is going to give us a continuous set of values, why not find MAX(RN), divide by 2 and then round? If the MAX(RN) is odd, you'll get the true median, if it's even you'll get rounded down. There's likely a cleaner way to do this but something like this:

  WITH cte AS (
        SELECT 
            temperatureID 
            ,castingID
            ,temperatureValue
            ,ROW_NUMBER() OVER (PARTITION BY castingID ORDER BY TemperatureDateTime) AS RN
        FROM Temperatures
)
SELECT
    * 
FROM cte AS c
INNER JOIN (
    SELECT
        castingID
        ,CEILING(CONVERT(DECIMAL(7,2),MAX(RN)) / 2) AS med
    FROM cte
    GROUP BY castingID
) AS m ON c.rn = m.med AND c.castingID = m.castingID

Here is a SQL Fiddle with the result of the query:
https://dbfiddle.uk/?rdbms=sqlserver_2019&fiddle=5b3aebf3ab4ced946c90a435d9edce3c

There's three use cases (all with different castingID).

1.) Odd number of rows

2.) Even number of rows

3.) A single row

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