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(<expr1>, <expr2>)
Arguments
Arguments | Description |
---|---|
<expr1> | Any numerical expression |
<expr2> | Any 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 |