Key Differences Observed in This Example

SELECT DISTINCT

The SELECT DISTINCT statement is used to retrieve unique values from a single column or a combination of columns in a table. It is often used when you want to eliminate duplicate rows from the result set....

GROUP BY

The GROUP BY clause is used to group rows that have the same values in specified columns into summary rows, like calculating aggregates (e.g., COUNT, SUM, AVG) for each group. It is typically used with aggregate functions....

Example of SELECT DISTINCT vs GROUP BY in MySQL

Let’s assume we have a customers table and an orders table. We are going to use these tables to show how DISTINCT and GROUP BY can be used for different use cases:...

Key Differences Observed in This Example

SELECT DISTINCT: Returns only unique city values, ignoring duplicates. GROUP BY: Groups customers by city and counts their orders, showing duplicate city entries with individual counts. Aggregate function: COUNT(*) is used with GROUP BY to summarize data within each group....

Purposes and Functionalities

SELECT DISTINCT:...

Conclusion

In MySQL, SELECT DISTINCT is used to retrieve unique values from one or more columns in a result set, eliminating duplicates without aggregation. Conversely, GROUP BY is employed to group rows sharing common values in specified columns, enabling aggregation functions to summarize data within each group. While SELECT DISTINCT is suitable for obtaining unique values, GROUP BY is essential for performing complex aggregations and generating summary results based on grouping criteria, each serving distinct purposes in MySQL query operations....