mysql索引的建立和删除

mysql索引的建立和删除

CREATE TABLE `student`(
	id INT UNIQUE NOT NULL,
	`name` VARCHAR(20) NOT NULL,
	email VARCHAR(30) NOT NULL,
	content VARCHAR(100) NOT NULL,
	PRIMARY KEY(id),
	UNIQUE unique_name(`name`),
	KEY plain_email(email),
	FULLTEXT fulltext_content(`content`)
)ENGINE=MYISAM DEFAULT CHARSET=utf8;

SHOW INDEX FROM student;
-- 删除索引
ALTER TABLE student DROP INDEX `unique_name`

ALTER TABLE student DROP INDEX `fulltext_content`

ALTER TABLE student DROP PRIMARY KEY;


-- 增加索引
CREATE FULLTEXT INDEX `fulltext_content` ON student(`content`);

ALTER TABLE student ADD UNIQUE INDEX `unique_name`(`name`);