关于数据库的一些小练习

 1 //查询所有品牌为“大众”的车型
 2 select * from t_car where version like ‘大众%‘
 3 
 4 //查询座位数不低于5座的车型
 5 select version,seat from t_car where seat >= 5
 6 
 7 //查询手动档中排量大于2的车型
 8 select version,displacement from t_car where displacement > 2
 9 
10 //查询押金低于10000且租金低于300的车型
11 select version,price,earnestMoney from t_car where price < 300 and earnestMoney < 10000
12 
13 //查询押金低于10000或租金低于300的车型
14 select version,price,earnestMoney from t_car where price < 300 or earnestMoney < 10000
15 
16 //查询所有车型，并按租金从高到低排序
17 select * from t_car order by price desc
18 
19 //统计车辆信息表中自动档和手动档车型的数
20 select gear,count(gear)数量 from t_car group by gear
21 
22 //找出每个品牌车辆的最高租金、最低租金、平均租金和车辆数量
23 select brand,max(price),min(price),avg(price),count(brand) from T_car group by brand
24 
25 //找出平均租金高于400的品牌
26 select brand,avg(price) as 平均租金 from t_car group by brand having avg(price) > 400
27 
28 //列出所有自动档车型，分页显示，每页显示3条数据，分别写出第一页、第二页、第三页的SQL语句
29 select version,gear from t_car limit 0,3
30 select version,gear from t_car limit 3,3
31 select version,gear from t_car limit 6,3