Leetcode Problem 1264. Page Recommendations

1264. Page Recommendations

Leetcode Solutions

Using Subqueries and Set Operations

Create a subquery to select all user2_id where user1_id is 1 (the user for whom we are recommending pages).
Create a second subquery to select all user1_id where user2_id is 1.
Combine the results of the two subqueries using the UNION operator to get a complete list of friends without duplicates.
Create a third subquery to select all page_id that user 1 already likes.
Write the main query to select distinct page_id from the Likes table where the user_id is in the list of friends obtained from step 3 and the page_id is not in the list of pages user 1 already likes from step 4.
Return the page_id as recommended_page.

erDiagram
    Friendship {
        int user1_id
        int user2_id
    }
    Likes {
        int user_id
        int page_id
    }
    Friendship ||--o{ Likes : "has"

Using Common Table Expressions (CTEs) and JOIN Operations

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Leetcode Problem 1264. Page Recommendations

Leetcode Solutions

Using Subqueries and Set Operations

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Query Steps

Code Implementation

Using Common Table Expressions (CTEs) and JOIN Operations

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