Understanding SQL Joins and Aggregate Functions

Grouping Data by Latest Entry Using R's Dplyr Package

Filtering Groups with Multiple Repeating Values in SQL

Optimizing SQL Queries for Conditional Summation

How to Select Latest Submission for Each Subject Using SQL GROUP BY as Inner Query

Finding Sailors Who Have Booked Every Boat: A Query-Based Approach

Counting Distinct IDs for Each Day within the Last 7 Days using SQL