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| DROP TABLE IF EXISTS `test_table`;
CREATE TABLE `test_table` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(20) DEFAULT NULL,
`type` enum('First','Second','Third','Last') DEFAULT NULL,
`set` set('First','Second','Third','Last') DEFAULT NULL,
`num` int(11) NOT NULL DEFAULT 0,
`price` decimal(10,2) NOT NULL DEFAULT 0.00,
PRIMARY KEY (`id`),
UNIQUE KEY `name` (`name`)
) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=latin1;
INSERT INTO `test_table` (`id`,`name`,`type`,`set`,`num`,`price`) VALUES
(1,'Art 1','First','Last',1,10.50),
(2,'Art 2','Second','First,Last',3,12.50),
(3,'Art 3','Second','Second,Last',2,15.50),
(4,'Art 4','Third','First,Second',5,25.50),
(5,'Art 5','Last','First,Last',2,5.50),
(6,'Art 6','First','First',12,1.50),
(7,'Art 7','Third','First,Third',20,1.75),
(8,'Art 8','Last','Second,Third',100,11.90);
select * from `test_table`;
select stddev_samp(name) from test_table;
select stddev_samp(num),stddev_samp(price),stddev_samp(`type`),stddev_samp(`set`) from test_table;
select stddev_samp(num),stddev_samp(price) from test_table where id>8;
/* as Window function */
SELECT name, `type`, price, stddev_samp(price)
OVER (PARTITION BY `type`) AS `stddev_samp` FROM test_table;
|
