数据库建索引

//------------　　建表　　------------　　

CREATE TABLE Person 
(
LastName varchar(30),
FirstName varchar(30), 
Address varchar(30), 
Age int(3) 
)

//------------　　建索引　　------------

CREATE INDEX PersonIndex
ON Person (LastName)

//------------　　建降序索引　　------------

CREATE INDEX PersonIndex
ON Person (LastName DESC)

//------------　　建多个索引　　------------

CREATE INDEX PersonIndex
ON Person (LastName, FirstName)