ROW_NUMBER() function in Snowflake?

Explained: ROW_NUMBER() function in Snowflake?

by

Are you looking to find how to use the ROW_NUMBER() function within the Snowflake cloud data warehouse or maybe you are looking for a solution, how to use the ROW_NUMBER function in the Snowflake? If you are looking for any of these problem solutions then you have landed on the correct page. I will also shmallas para hombre nike balmain carbone fragrantica cheap jerseys mikrobølgeovn med grill og varmluft miroir terzo jayden daniels jersey jayden daniels jersey nike air max aliexpress balmain carbone fragrantica meia com pompom Purchase Florida state seminars jerseys, football, and various accessories for Florida state seminars adidas yeezy shoes adidas yeezy 700 v3 air nike sneakers golf dow you what and how to use ROW_NUMBER() function. I will explain the ROW_NUMBER() function by taking a practical example. So don’t waste time let’s start step by step guide to understanding what is the ROW_NUMBER() expression.onlysxm.com janwoodharrisart.com jorgensenfarmsinc.com blutuszos mennyezeti lámpa team easy on tøj til salg חליפות מידות גדולות נשים lepetitartichaut.com greensandseeds.com janwoodharrisart.com mindfulmusclellc.com onlysxm.com massage pistol team easy on tøj til salg massage pistol jorgensenfarmsinc.com

What is ROW_NUMBER() Function?

ROW_NUMBER() function helps to return the unique row number within each row. For example, if I want to know specific data i.e. ‘John’ which is present in the 20th row, then the row_number will be displayed for that particular data is 20.

How can we use the ROW_NUMBER() Function ?

ROW_NUMBER() function is used to return a unique row number for each row within a window partition. The row number starts at 1 and continues up sequentially.

What is the Syntax of ROW_NUMBER() function in Snowflake?

-- Syntax : 

ROW_NUMBER () over ( [partition by expression-1[,..]] [order by expression-2,[…]] [ ASC | DESC ])

ROW_NUMBER() Argument Details :

Here we are having only expressions that will be used depending on the requirement.

  • Expression-1 specifies the columns or expressions to partition by. we can partition by 0, 1, or more expressions. For example, If you are selecting data across multiple states and you want a row number from 1 to N within each state then in that case we can partition by the state.
  • Expression-2 specifies the columns or expressions that will be used to determine the order of the rows. We can order 1 or more by expressions. For example, If we want to list the farmers in order by the production of corn.

Full Example of ROW_NUMBER() function in Snowflake:

-- Create a Table

create or replace TABLE EMP (
ID NUMBER(38,0),                                                                         
NAME VARCHAR(30) COMMENT 'NAME OF THE EMPLOYEE',                                                                         
INFO VARCHAR(20) DEFAULT 'NOT-NULL'  
)

-- Insert data

Insert into demo.public.emp(id,name) values(1,'Ram'),(2,'RAJU'),(3,'Sameer'), (4,'Sai Kumar'), (5,'Naveen Sai'), (6,'Seshi Kumar'),(7,'Rajiv Ram');

-- Select the Table data

select * from demo.public.emp;

+----+-------------+----------+
| ID | NAME        | INFO     |
|----+-------------+----------|
|  1 | Ram         | NOT-NULL |
|  2 | RAJU        | NOT-NULL |
|  3 | Sameer      | NOT-NULL |
|  4 | Sai Kumar   | NOT-NULL |
|  5 | Naveen Sai  | NOT-NULL |
|  6 | Seshi Kumar | NOT-NULL |
|  7 | Rajiv Ram   | NOT-NULL |
+----+-------------+----------+

-- Apply ROW NUMBER to table data

select state, bushels_produced, row_number()
  over (order by bushels_produced desc)
  from corn_production;

+--------+------------------+------------+
|  state | bushels_produced | ROW_NUMBER |
+--------+------------------+------------+
| Kansas |              130 |           1|
| Kansas |              120 |           2|
| Iowa   |              110 |           3|
| Iowa   |              100 |           4|
+--------+------------------+------------+

select
  symbol,
  exchange,
  shares,
  row_number() over (partition by exchange order by shares) as row_number
from trades;

+------+--------+------+----------+
|SYMBOL|EXCHANGE|SHARES|ROW_NUMBER|
+------+--------+------+----------+
|SPY   |C       |   250|         1|
|AAPL  |C       |   250|         2|
|AAPL  |C       |   300|         3|
|SPY   |N       |   100|         1|
|AAPL  |N       |   300|         2|
|SPY   |N       |   500|         3|
|QQQ   |N       |   800|         4|
|QQQ   |N       |  2000|         5|
|YHOO  |N       |  5000|         6|
+------+--------+------+----------+

As we can see from the above example we got the row numbers according to the Exchange data as expected.

When you should use ROW_NUMBER() Function in Snowflake?

There are certain use case scenarios when it is recommended to use the ROW_NUMBER function within the Snowflake cloud data warehouse which are as follows:

  • You want to apply the row number to a table data to get the sequential order.
  • You want to get unique id’s for a table data.

Real World Use Case Scenarios for ROW_NUMBER Function in Snowflake.

  • The persons standing in a queue in sequential order.
  • The number plates for vehicle registration.
  • House numbers will also be in such an order to use row number.

ROW_NUMBER() Snowflake Official Documentation Link

Final Thoughts

In this article, we have learned about ROW_NUMBER() function and uses with the examples explained clearly. I have also covered different scenarios with a practical example that could be possible. I hope the information that was provided is helped in gaining the knowledge.

Please share your comments and suggestions in the comment section below and I will try to answer all your queries as time permits.

Join Telegram Group
Download Free Azure Videos
Connect on LinkedIn

Revanth Kumar