# GROUP BY Clause

The `GROUP BY` clause organizes the rows returned from a `SELECT` statement into groups. Within each group, you can apply an aggregate function, like `count()` or `sum()` to get the number of items or sum, respectively.

In this example, the `SELECT` query counts the number of rows for each category and groups the counts by category.

```nolang
SELECT Category, COUNT(*) AS "cnt"
FROM "Superstore"
GROUP BY Category;

```

| Category        | cnt   |
| --------------- | ----- |
| Furniture       | 2,121 |
| Office Supplies | 6,026 |
| Technology      | 1,847 |

You can also group by multiple columns. This query generates the group of cities that contain stores in each category. The count column shows how many stores there are in each city.

```nolang
SELECT Category, City, count(*) as cnt
FROM "Superstore"
GROUP BY Category, City
```

Here are the first ten results.

| Category  | City         | cnt |
| --------- | ------------ | --- |
| Furniture | Akron        | 2   |
|           | Alexandria   | 3   |
|           | Allen        | 1   |
|           | Allentown    | 1   |
|           | Amarillo     | 4   |
|           | Anaheim      | 8   |
|           | Andover      | 1   |
|           | Apopka       | 1   |
|           | Apple Valley | 2   |

:::note
Grouping by ordinal number is not supported. You can't refer to a results column or an expression created by input values by its index value. To shorten a lengthy expression in your query, use an alias. For example, this query throws an error.

```nolang
SELECT Category, City, count(*) as cnt
FROM "Superstore"
GROUP BY 1, 2
```
:::