9 Aug 2026, 11:28 UTC535 views1 reactionsread 31 August 2026 Question:
Given this data:
id | date | x
1 | 2026-01-01 | 10
1 | 2026-01-05 | 20
1 | 2026-01-10 | 30
1 | 2026-01-15 | 40
1 | 2026-01-20 | 50
2 | 2026-01-02 | 100
2 | 2026-01-06 | 200
2 | 2026-01-11 | 300
2 | 2026-01-16 | 400
2 | 2026-01-21 | 500
Question:
For each id, return the latest 3 dates and their corresponding x values as separate columns.
Expected output:
id | x_1 | x_2 | x_3
1 | 50 | 40 | 3β¦
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21 Jan 2024, 14:08 UTCβ9,000 views15 reactionsread 31 August 2026 When assigning unique identifiers to rows based on a specified order, three key functions come into play: ROW_NUMBER, RANK, and DENSE_RANK.
Consider the following table:
| Name | Score |
|-------- |-------|
| Alice | 90 |
| Bob | 90 |
| Carol | 85 |
| David | 78 |
ROW_NUMBER:
The simplest of the three, ROW_NUMBER assigns a unique number to each row based on the specified order. Eaβ¦
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18 Apr 2022, 20:32 UTCβ25,400 views86 reactionsread 31 August 2026 Here's a snippet of code written in C:
for(int i=0;i<n;i++)
{
for(int j=0;j<n;j++)
{
//some operation
}
}
How can I write something equivalent in SQL?
Solution:Alias
say, you are asked to count the frequency of each color occurring in the same table , so you can write something like this:
select distinct color ,(select count(*) from colors where c.color=color) from colors c;
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7 Sept 2021, 03:02 UTCβ32,100 views11 reactionsread 31 August 2026 https://dataengineeringacademy.medium.com/5-sql-queries-every-data-engineer-scientist-should-know-d68261167f1a
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20 May 2021, 05:17 UTCβ33,900 views6 reactionsread 31 August 2026 File
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20 May 2021, 05:14 UTCβ32,900 views5 reactionsread 31 August 2026 File
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15 May 2021, 05:40 UTCβ29,800 views4 reactionsread 31 August 2026 https://towardsdatascience.com/mysql-vs-postgresql-3d48891452a
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20 Feb 2021, 05:24 UTCβ27,200 views6 reactionsread 31 August 2026 https://play.google.com/store/apps/details?id=com.sololearn.sql
If you are starting with SQL and wish to code the queries as you learn more about SQL , Sololearn is perfect place for you.
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7 Dec 2020, 01:05 UTCβ26,500 views5 reactionsread 31 August 2026 https://www.udemy.com/course/the-complete-sql-course-2020-become-a-mysql-master/?couponCode=SQLCOURSE29
Get this course for free.
Just two days before it expires.
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8 Aug 2020, 16:09 UTCβ24,500 views6 reactionsread 31 August 2026 Photo
Photo, posted without a caption
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8 Aug 2020, 16:09 UTCβ23,100 views5 reactionsread 31 August 2026 Photo
You are given this database, your task is to outputβ‘
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22 Jul 2020, 16:39 UTCβ21,300 views6 reactionsread 31 August 2026 Write a sql query to find the Joining date of Employee in YYYY-DAY-Date format.
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