表结构如下：

flight{flightID,StartCityID ,endCityID,StartTime}

city{cityID, CityName)

实验环境：

create table city(cityID int auto_increment primary

key,cityName varchar(20));

create table flight (flightID int auto_increment primary key,

StartCityID int references city(cityID),

endCityID int references city(cityID),

StartTime timestamp);

//航班本来应该没有日期部分才好，但是下面的题目当中涉及到了日期

insert into city values(null,'北京'),(null,'上海'),(null,'广州');

insert into flight values

(null,1,2,'9:37:23'),(null,1,3,'9:37:23'),(null,1,2,'10:37:23'),(null,2,3,'10:37:23');

1、查询起飞城市是北京的所有航班，按到达城市的名字排序

参与运算的列是我起码能够显示出来的那些列，但最终我不一定把它们显示出来。各个表组合出来的中间结果字段中必须包含所有运算的字段。

select * from flight f,city c

where f.endcityid = c.cityid and startcityid =

(select c1.cityid from city c1 where c1.cityname = "北京")

order by c.cityname asc;

mysql> select flight.flightid,'北京' startcity, e.cityname from

flight,city e wh

ere flight.endcityid=e.cityid and flight.startcityid=(select

cityid from city wh

ere cityname='北京');

mysql> select flight.flightid,s.cityname,e.cityname from

flight,city s,city e wh

ere flight.startcityid=s.cityid and s.cityname='北京' and

flight.endCityId=e.cit

yID order by e.cityName desc;

2、查询北京到上海的所有航班纪录(起飞城市，到达城市，起飞时间，航班号)                   select c1.CityName,c2.CityName,f.StartTime,f.flightID                   from city c1,city c2,flight f                   where f.StartCityID=c1.cityID                   and f.endCityID=c2.cityID                   and c1.cityName='北京'                   and c2.cityName='上海'                   3、查询具体某一天(2005-5-8)的北京到上海的的航班次数                   select count(*) from                   (select c1.CityName,c2.CityName,f.StartTime,f.flightID                   from city c1,city c2,flight f                   where f.StartCityID=c1.cityID                   and f.endCityID=c2.cityID                   and c1.cityName='北京'                   and c2.cityName='上海'                   and 查帮助获得的某个日期处理函数(startTime) like '2005-5-8%'                   mysql中提取日期部分进行比较的示例代码如下：                   select * from flight where                   date_format(starttime,'%Y-%m-%d')='1998-01-02'