Summarizing Multiple Columns with dplyr: A Categorical Version

Counting Entries in a Data Frame in R: A Comprehensive Guide

Counting Single Matching Records with the Same AnswerCount Value in the Stack Exchange Database Using SQL Queries

Removing Observations with Filters in R Using Dplyr Library: A Step-by-Step Guide

Calculating Averages in SQL: A Comprehensive Guide to Derived Tables and Subqueries

Understanding Missing Values in R: Techniques for Handling and Classifying Variables

Counting Frequencies of Values in Two Columns Using R

Counting Values in Column with Ranges Given a Specific Condition