問(wèn)題描述

DROP TABLE IF EXISTS merchants;CREATE TABLE merchants (id int(10) unsigned NOT NULL AUTO_INCREMENT,name varchar(255) DEFAULT NULL,ip char(15) DEFAULT NULL, PRIMARY KEY (id)) ENGINE=MyISAM AUTO_INCREMENT=7 DEFAULT CHARSET=utf8;

-- ------------------------------ Records of merchants-- ----------------------------INSERT INTO merchants VALUES (’1’, ’abc.com’, ’127.0.0.1’);INSERT INTO merchants VALUES (’2’, ’abc.com’, ’127.0.0.1’);INSERT INTO merchants VALUES (’3’, ’abc.com’, ’112.112.112.112’);INSERT INTO merchants VALUES (’4’, ’bbc.com’, ’127.0.0.1’);INSERT INTO merchants VALUES (’5’, ’bbc.com’, ’127.0.0.1’);

這是mysql語(yǔ)句,我想實(shí)現(xiàn)abc.com 有效ip為2bbc.com 有效ip為1這語(yǔ)句怎么寫(xiě),求大神指點(diǎn)指點(diǎn)！謝謝！

問(wèn)題解答

SELECT `name`, COUNT(DISTINCT ip) AS ’有效IP’ FROM merchants GROUP BY `name`