Video 314: This is the 13th video of the SQL Interview Question series.

00:00 - Introduction to dataset and Question
02:05 - Approach 1: General Aggregate Logic
03:25 - Approach 2: Using Window Function
05:55 - Conclusion

We are given the User's Activity table which has player id, device_id, event_date and number of games played
Player ID and the event date forms the unique identifier

we are asked to Write a solution to find the first login date for each player.

To solve the problem of finding the first login date for each player, we can use the SQL MIN function in combination with the GROUP BY clause.

In this video, we'll explore how to find the first login date for each player using two different SQL approaches.

*** Approach 1: General Aggregate Logic ***
This approach utilizes the MIN() function to find the earliest event date for each player. By grouping the results by player_id, we can easily identify the first login date.

*** Approach 2: Using Window Function ***
In this method, we leverage window functions to assign a rank to each event date for each player. The ROW_NUMBER() function helps us determine the earliest login date by ordering the event dates in ascending order and selecting the top-ranked date for each player.

For a comprehensive understanding of these SQL methodologies and their application, please refer to this explanatory video.

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