聊聊索引失效的十种场景,太坑了

复制CREATETABLE `user` ( `id` intNOTNULL AUTO_INCREMENT,太坑了 `code` varchar(20) COLLATE utf8mb4_bin DEFAULTNULL, `age` intDEFAULT0, `name` varchar(30) COLLATE utf8mb4_bin DEFAULTNULL, `height` intDEFAULT0, `address` varchar(30) COLLATE utf8mb4_bin DEFAULTNULL, PRIMARYKEY (`id`), KEY `idx_code_age_name` (`code`,`age`,`name`), KEY `idx_height` (`height`) ) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin 1.2.3.4.5.6.7.8.9.10.11.