Is it possible to GROUP BY multiple columns using MySQL?

Detailed insight

Column sequence: the silent sorter

The order of columns in your GROUP BY clause is not just a stylistic choice. It defines the pecking order, like who gets served first at a dinner party. Remember, a properly set column order ensures an efficiently sorted MySQL output.

Grouping game with CONCAT

Want to fuse multiple columns into a closely-knit group? Meet your new friend CONCAT:

SELECT CONCAT(col1, '-', col2) AS group_key, COUNT(*) // DIY unique identifier!
FROM table
GROUP BY group_key;


It's like hosting a dinner party and making a seating plan based on people's love for pizza or tofu. Mainstream but impressive.

Unique counts with DISTINCT

When your goal is to count distinct values within each group, employ DISTINCT:

SELECT col1, col2, COUNT(DISTINCT col3) // The DISTINCT nuance!
FROM table
GROUP BY col1, col2;


It's like registering unique conversations at a party. Who talked about Godzilla? Count 'em!

Complex data, simple solutions

For more complex cases, use GROUP BY with multiple columns to dissect your data and perform a multi-organ analysis. It's a life-saver when your boss asks for a complex report. You can thank me later!

Advanced practices

The power of subquery & joins

When GROUP BY is not fancy enough, dial it up a notch with subqueries or joins. This allows complex cocktails of grouped and pre-processed data. Caution: Too many may result in a hangover!

Aggregate functions: secret superheroes

To dig deeper into your data, use MySQL's aggregate functions like AVG, MAX, MIN, SUM, within your GROUP BY queries. It’s like having superpowers, but for data analysis.

NULL and other quirks

Remember how MySQL treats NULL values? They form a group of their own, just like the cool kids at school! Also, watch out for implicit grouping when columns in the SELECT list aren't in the GROUP BY clause. That can be the party pooper!