废话不多说，只接上SQL语句

方式一：

单一索引

CREATE INDEX index_nameUSING BTREE ONtable_name (column_name);

复合索引(组合索引)

CREATE INDEX index_nameUSING BTREE ONtable_name (column1, column2, ...);

方式二:

单一索引

ALTER TABLE table_nameADD INDEX index_name USING BTREE (column_name);

复合索引(组合索引)

ALTER TABLE table_nameADD INDEX index_name USING BTREE (column1, column2, ...);

实际执行例如：

用户表：

CREATE TABLE `person` (    
	`id` INT NOT NULL,  
	`name` VARCHAR ( 100 ) DEFAULT NULL,  
	`email` VARCHAR ( 100 ) DEFAULT NULL,  
	`age` INT DEFAULT NULL,  
PRIMARY KEY ( `id` )   
) ENGINE = INNODB COMMENT = '用户'; 

执行任意一个：

CREATE INDEX idx_example  USING BTREE ON person ( name, email, age );
ALTER TABLE person ADD INDEX  idx_example USING BTREE (name, email, age);

结果：

CREATE TABLE `person` (
	`id` INT NOT NULL,
	`name` VARCHAR ( 100 ) DEFAULT NULL,
	`email` VARCHAR ( 100 ) DEFAULT NULL,
	`age` INT DEFAULT NULL,
	PRIMARY KEY ( `id` ),
	KEY `idx_example` ( `name`, `email`, `age` ) USING BTREE
) ENGINE = INNODB COMMENT = '用户';