一、创建索引
1.PRIMARYKEY(主键索引) mysql > ALTERTABLE`table_name`ADDPRIMARYKEY (`column`) 2.UNIQUE(唯一索引) mysql > ALTERTABLE`table_name`ADDUNIQUE (`column` ) 3.INDEX(普通索引) mysql > ALTERTABLE`table_name`ADDINDEX index_name (`column`) 4.FULLTEXT(全文索引) mysql > ALTERTABLE`table_name`ADDFULLTEXT ( `column` ) 5.多列索引(组合索引) mysql > ALTERTABLE`table_name`ADDINDEX index_name (`column1`,`column2`,`column3`)
CREATE TABLE table_name ( ID INT NOT NULL, username VARCHAR(16) NOT NULL, city VARCHAR(50) NOTNULL, age INT NOT NULL );
二、删除索引
删除索引的语法: DROP INDEX [ indexName ] ON mytable;
后面继续更新!