Grouping results with GROUP BY
Using GROUP BY in SQL allows you to group results based on one or more columns. This is useful for performing aggregations such as counting, summing, or averaging data.
Syntax
The basic syntax for using GROUP BY in SQL is:SELECT [columns] FROM [table] GROUP BY [column];
You can use GROUP BY along with aggregate functions like COUNT, SUM, and AVG.
Purpose
Grouping results is essential for data analysis. It allows you to:
- Count how many products are in each category.
- Calculate the total revenue for each product type.
- Get the average price per category.
Exercises
Interactive Test 1: Drag and Drop
Drag in the corresponding order.
Drag the options:
SELECT
category
FROM
GROUP BY
Completa el código:
______
______
______
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Interactive Test 2: Fill in the Blanks
Fill the Blanks.
SELECT category, COUNT(*) FROM products GROUP BY ;
Practical Exercise:
Statement:
Write an SQL query to count the number of products in each category.
Example Data
| id | name | age |
|---|---|---|
| 1 | John | 25 |
| 2 | Anna | 30 |
| 3 | Louis | 22 |
| 4 | Martha | 35 |
* Write your SQL query and execute to see results.
Results:
No results available.