# sum

[Read this page in HTML](https://www.scopedb.io/docs/reference/functions/aggregate/sum)

Returns the sum of non-NULL values.

## Syntax

```scopeql
sum(<expr>)
```

## Arguments

| Argument | Type                      | Description  |
| -------- | ------------------------- | ------------ |
| `<expr>` | `int`, `uint`, or `float` | Input value. |

## Returns

Returns the same numeric type as the input. Returns NULL for empty input or when every value is NULL.

## Examples

Payment events use positive amounts for captures and negative amounts for refunds. Sum the signed amounts to calculate net sales by store.

```scopeql
VALUES
    ('north', 'captured', 12000), ('north', 'captured', 8000),
    ('north', 'refunded', -3000), ('south', 'captured', 4500)
SELECT $0 AS store, $1 AS event, $2 AS amount_cents
GROUP BY store
AGGREGATE sum(amount_cents) AS net_sales_cents
ORDER BY store
```

```text
+-------+-----------------+
| store | net_sales_cents |
+-------+-----------------+
| north | 17000           |
| south | 4500            |
+-------+-----------------+
```