MySQL 存储过程计算直线斜率 - 1-7 分钟时间与对应值

DELIMITER // CREATE PROCEDURE calculate_slope() BEGIN DECLARE sum_x FLOAT; DECLARE sum_y FLOAT; DECLARE sum_xy FLOAT; DECLARE sum_x_squared FLOAT; DECLARE slope FLOAT;

SET sum_x = 0; SET sum_y = 0; SET sum_xy = 0; SET sum_x_squared = 0;

SELECT SUM(time) INTO sum_x FROM data;

SELECT SUM(value) INTO sum_y FROM data;

SELECT SUM(time*value) INTO sum_xy FROM data;

SELECT SUM(time*time) INTO sum_x_squared FROM data;

SET slope = ((COUNT() * sum_xy) - (sum_x * sum_y)) / ((COUNT() * sum_x_squared) - (sum_x * sum_x));

SELECT slope AS 'Slope of the line'; END // DELIMITER ;

CALL calculate_slope();