Finding the row corresponding to the Nth value in each group by in SQL

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I have a table A as follows:

name   course  grade
Bob      C1     12
Bob      C2     13
Bob      C3     23
Bob      C4     17 
James    C2     15
James    C6     27
Nick     C5    18
Nick     C1    16
Nick     C3    22
Nick     C2    32
Nick     C7    19

I want a query that can return the student name and the course number for each student corresponding to the 3rd highest grade for that student. For example, in the table above, the 3rd highest grade for Bob is 17 so the course number is C4. Also since James has fewer than 3 courses, his course should not be included in the query result. In other words, the query result should show this:

name course_id
Bob    C4
Nick   C7

What would be the query that can do that?

In standard SQL one would do this using window functions:

select name, course
from (
   select name, course, grade, 
          dense_rank() over (partition by name order by grade) as rnk
   from grades
) t
where rnk = 3

Online example: https://rextester.com/YOHZB50840

Online example with MySQL: https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=3f9ff551c89f6941dbf8e424e6dfda56

How to Get the First or Last Value in a Group Using Group By in SQL , Finding the row corresponding to the Nth value in each group by in SQL I want a query that can return the student name and the course number for each� Finding the desired rows is the hard part. In my previous articles I focused on extrema: The single biggest/smallest/extremest row in each group. (Pretty easy.) The N most extreme rows in each group. (Doable, but harder.) In this article, we’re going to see how to get not the most extreme row, not the N most extreme rows, but—hold your

use corelated subquery and row_number analytic function which support most dbms

with cte as 
  ( select t1.* from table t1 where 
           exists ( select 1 from table t2 where t1.name=t2.name
                                 group by name 
                                 having count(distinct course)>=3
                  )
  ) , 
 cte2 as 
  (
select * ,row_number() over(partition by name order by grade asc) rn 
from cte
  ) select * from cte2 where rn=3

SELECT every nth value by Date from large table, Getting the last value of a group in an aggregated query in 7 | 1 | withdraw | 2019-08-03 16:15:09+03 | {"delta_balance": -50} (7 rows) The first elements of both arrays are equal (1), so PostgreSQL moves on to the next element. It works by calculating the aggregates using the window function on the� T-SQL – How to Select Top N Rows for Each Group Using ROW_NUMBER() Posted on July 11, 2015 Written by Andy Hayes 17 Comments I’ve recently been working on a data migration project and have found myself utilizing the ROW_NUMBER() function in SQL Server a lot.

You can try using row_number()

    select name, course
    from (
       select name, course, grade, 
              row_number() over (partition by name order by grade desc) as rn
       from grades
    ) t where rn = 3

Select row at the nth percentile, for all rows, calculate M = P mod R, and store that value in a corresponding M column for all data. Select data where M = x where x is any number� SQL ROW_NUMBER Function Example. The SQL ROW_NUMBER Function allows you to assign the rank number to each record present in a partition. In this example, we show you how to Select First Row from each SQL Group. The following SQL Query will. First, partition the data by Occupation and assign the rank number using the yearly income.

SQL, Use the window function ntile() in a subquery (requires Postgres 8.4 or later). Then select the segments you are interested in (corresponding to� First, the PARTITION BY clause divides the result set returned from the FROM clause into partitions. The PARTITION BY clause is optional. If you omit it, the whole result set is treated as a single partition. Then, the ORDER BY clause sorts the rows in each partition.

Impala Analytic Functions | 5.6.x, The GROUP BY Statement in SQL is used to arrange identical data into and their corresponding SALARY is the sum of the SALARY of duplicate rows. The SUM() function of SQL is used here to calculate the sum. This means to place all the rows with same values of both the columns column1 and column2 in one group. It determines the percentile value of each row. Its syntax is as follows: Percent_rank() Over(Partition by <expression> Order by <expression>) Although the partition clause is optional. Let’s use this function to determine the amount percentile of each customer in the table. Nth_value ; Sometimes you want to find out which row had the highest

How to Select the Nth Greatest/Least/First/Last Row in SQL, Unlike a corresponding GROUP BY query, this one can analyze a single ahead to subsequent rows and find the last value for each country. So each row in the outer query is evaluated first and the inner query is run for that row. Let’s look into the background process of this query, by substituting a value for N i.e. 4,(Idea is to find the 4th maximum salary):

Comments
  • And what if there are ties? Your question is not clear.
  • @a_horse_with_no_name let's say it's MySQL
  • Can you please use your code using an online sql editor. I tried using this link and it gave me error: sqltest.net
  • @JamesRobisnon: then apparently your DBMS does not support modern SQL I have added an online example