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COVAR_SAMP

Aggregate function.

The covar_samp() function returns the sample covariance (Σ((x - x̅)(y - y̅)) / (n - 1)) of two data columns.

caution

NULL values are not counted.

Syntax

COVAR_SAMP(expr0, expr1)

Arguments

ArgumentsDescription
expression0Any numerical expression
expression1Any numerical expression

Return Type

float64, when n <= 1, returns +∞.

Example

Create a Table and Insert Sample Data

CREATE TABLE store_sales (
id INT,
store_id INT,
items_sold INT,
profit FLOAT
);

INSERT INTO store_sales (id, store_id, items_sold, profit)
VALUES (1, 1, 100, 1000),
(2, 2, 200, 2000),
(3, 3, 300, 3000),
(4, 4, 400, 4000),
(5, 5, 500, 5000);

Query Demo: Calculate Sample Covariance between Items Sold and Profit

SELECT COVAR_SAMP(items_sold, profit) AS covar_samp_items_profit
FROM store_sales;

Result

| covar_samp_items_profit |
|-------------------------|
| 250000.0 |