How can I use “postgres_group_concat” for retrieving the interest group?

298    Asked by DelbertRauch in SQL Server , Asked on Dec 28, 2023

 I am currently working on a database schema for a social media platform where users can join multiple interest groups. How can I utilize the “GROUP_CONCAT” or other similar functions in PostgreSQL for retrieving the interest group of a user? 

Answered by Danilo Guidi

If you want to concatenate values by using the “Postgres group_concat” in SQL then there is a “STRING_AGG” which can ease the task for you. It can concatenate values from diverse or multiple rows into a single string even with a required delimiter. Another tool that can help you with this could be “GROUP_CONCAT”.

Here is the example query given:-

SELECT user_id, STRING_AGG( interest_ group, ',') AS joined_groups
FROM user_interests
GROUP BY user_id;

This above coding analogy can certainly retrieve the interest group of users from the “user_interests” table and then it will group them by using the “user_id”.

Here is the example given:-

Assume the user_interests table:

User_id interest_group

1 Sports

1 Music

2 Movies

2 Sports

2 Travel

Running the provided.STRING_AGG query would output:

User_id joined_groups

1 Sports, Music

2 Movies, Sports, Travel



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