sumArray

Example of using the sumArray combinator

sumArray

Description

The Array combinator can be applied to the sum function to calculate the sum of all elements in an array, using the sumArray aggregate combinator function.

The sumArray function is useful when you need to calculate the total sum of all elements across multiple arrays in a dataset.

Example usage

In this example, we’ll use a sample dataset of daily sales across different product categories to demonstrate how sumArray works. We’ll calculate the total sales across all categories for each day.

Query

CREATE TABLE daily_category_sales
(
    date Date,
    category_sales Array(UInt32)
) ENGINE = Memory;

INSERT INTO daily_category_sales VALUES
    ('2024-01-01', [100, 200, 150]),
    ('2024-01-02', [120, 180, 160]),
    ('2024-01-03', [90, 220, 140]);

SELECT 
    date,
    category_sales,
    sumArray(category_sales) AS total_sales_sumArray,
    sum(arraySum(category_sales)) AS total_sales_arraySum
FROM daily_category_sales
GROUP BY date, category_sales;

The sumArray function will sum up all elements in each category_sales array. For example, on 2024-01-01, it sums 100 + 200 + 150 = 450. This gives the same result as arraySum.

See also

• sum
• arraySum
• Array combinator
• sumMap