[PostgreSQL] (Medium) User's Third Transaction [Uber SQL Interview Question]

SELECT user_id, spend, transaction_date
FROM (
  SELECT * 
       , ROW_NUMBER() OVER (PARTITION BY user_id ORDER BY transaction_date) AS ROW
  FROM transactions) TB
WHERE ROW = 3;

 

1. row_number() 는 mysql이랑 문법이 같은 듯!

 

2. row==3 하고 왜 안 되지 했다

 

 

출처

https://datalemur.com/questions/sql-third-transaction