Optimizing PostgreSQL Queries: A More Efficient Approach for Retrieving Customer Book Purchase Data

Retrieving the Latest Record from Duplicate Values Without Grouping in MySQL

SELECT DISTINCT ON (user_id, activity_type_id, EXTRACT(year FROM start_date_local))

Filtering SQL Server Data According to Its Max Value

Calculating the Average of Last 3 Values for Each User in SQL

SELECT DISTINCT ON (label) * FROM products ORDER BY label, created_at DESC;

Retrieving Maximum Values: Sub-Query vs Self-Join Approach