sql练习-基础练习

闲来无事，找个网站练习sql基础。
练习网站：
https://zh.sqlzoo.net/wiki/SQL_Tutorial

练习区域，左边导航栏
SELECT within SELECT Tutorial/zh

2.列出欧洲每国家的人均GDP，当中人均GDP要高于英国’United Kingdom’的数值。

select name
  from world
 where continent = 'Europe'
   and (gdp / population) >
       (select gdp / population from world where name = 'United Kingdom');

3.在阿根廷Argentina 及 澳大利亚 Australia所在的洲份中，列出当中的国家名字 name 及洲分 continent 。按国字名字顺序排序。

select name, continent
  from world
 where continent in (select continent
                       from world
                      where name = 'Argentina '
                         or name = 'Australia')
 order by name

4.哪一个国家的人口比加拿大Canada的多，但比波兰Poland的少?列出国家名字name和人口population 。

select name, population
  from world
 where population > (select population from world where name = 'Canada')
   and population < (select population from world where name = 'Poland')

5.Germany德国（人口8000万），在Europe欧洲国家的人口最多。Austria奥地利（人口850万）拥有德国总人口的11％。
显示欧洲的国家名称name和每个国家的人口population。以德国的人口的百分比作人口显示。

select name,
       concat(round(population /(select population from world where name = 'Germany') * 100),'%')
  from world
 where continent = 'Europe'

6.哪些国家的GDP比Europe欧洲的全部国家都要高呢? [只需列出 name 。] (有些国家的记录中，GDP是NULL，沒有填入资料的。)

select name
  from world
 where gdp > all (select gdp
          from world
         where gdp > 0
           and continent = 'Europe')

7.在每一个州中找出最大面积的国家，列出洲份 continent, 国家名字 name 及面积 area。 (有些国家的记录中，AREA是NULL，沒有填入资料的。)

select continent, name, area
  from world x
 where area >= all (select area
          from world y
         where y.continent = x.continent
           and area > 0)

8.列出洲份名称，和每个洲份中国家名字按子母顺序是排首位的国家名。(即每洲只有列一国)

select continent, name
  from (select continent,
               name,
               row_number() over(partition by continent order by name) as num
          from world) a
 where a.num = '1';

9.找出洲份，当中全部国家都有少于或等于 25000000 人口. 在这些洲份中，列出国家名字name，continent 洲份和population人口。

select name, continent, population
  from world a
 where (select max(population) from world b where a.continent = b.continent) <= 25000000

10.有些国家的人口是同洲份的所有其他国的3倍或以上。列出 国家名字name 和 洲份 continent。

select name, continent
  from world a
 where (select a.population / 3 >= all (select population
                                    from world b
                                   where a.continent = b.continent
                                     and a.name != b.name))

2020/4/28更新
练习区域，左边导航栏
join

1.要找出德国队球员

SELECT matchid,player FROM goal 
  WHERE teamid = 'GER'

2.只显示赛事1012的 id, stadium, team1, team2

SELECT id,stadium,team1,team2
  FROM game where id = '1012'

3.显示每一个德国入球的球员名，队伍名，场馆和日期。

SELECT player, teamid, stadium, mdate
  FROM game
  JOIN goal
    ON (id = matchid)
   and teamid = 'GER'

4.列出球员名字叫Mario (player LIKE ‘Mario%’)有入球的 队伍1 team1, 队伍2 team2 和 球员名 player

select team1, team2, player
  from game
  join goal
    on player like 'Mario%'
   and id = matchid

5.列出每场球赛中首10分种gtime<=10有入球的球员 player, 队伍teamid, 教练coach, 入球时间gtime

SELECT player, teamid, coach, gtime
  FROM goal
  join eteam
    on teamid = id
 WHERE gtime <= 10

6.列出’Fernando Santos’作为队伍1 team1 的教练的赛事日期，和队伍名。

select mdate, teamname
  from eteam
  join game
    on (team1 = eteam.id)
   and coach = 'Fernando Santos'

7.列出场馆 'National Stadium, Warsaw’的入球球员。

select player
  from goal
  join game
    on matchid = id
   and stadium = 'National Stadium, Warsaw'

8.列出全部赛事，射入德国龍門的球员名字。

SELECT distinct (player)
  FROM game
  JOIN goal
    ON matchid = id
   and ((team1 = 'GER' and team2 = teamid) or
       (team1 = teamid and team2 = 'GER'))

9.列出队伍名称 teamname 和该队入球总数.

select teamname, count(teamname)
  from eteam
  join goal
    on id = teamid
 group by teamname
 order by teamname

10.列出场馆名和在该场馆的入球数字。

select stadium, count(*)
  from game
  join goal
    on id = matchid
 group by stadium
 order by stadium

11.每一场波兰’POL’有参与的赛事中，列出赛事编号 matchid, 日期date 和入球数字.

select matchid, mdate, count(*)
  from game
  join goal
    on matchid = id
 where (team1 = 'POL' or team2 = 'POL')
 group by matchid, mdate

12.每一场德国’GER’有参与的赛事中，列出赛事编号 matchid, 日期date 和德国的入球数字。

select matchid, mdate, count(*)
  from game
  join (select matchid, teamid from goal where teamid = 'GER') a
    on a.matchid = id
 group by matchid, mdate

13.列出所有比赛的每个队的比分

select 
b.mdate,
b.team1,
   sum(case when teamid=team1 then 1 else 0 end) as score1, 
b.team2,
   sum(case when teamid=team2 then 1 else 0 end) as score2 
from 
(select id ,mdate, team1, team2 from game) b 
left join 
(select matchid, teamid from goal) a 
on a.matchid = b.id 
group by b.mdate, b.team1, b.team2 
order by b.mdate, b.team1, b.team2;

2020/5/13更新
练习区域，左边导航栏
more join

1.列出電影北非諜影 'Casablanca’的演員名單。

select a.name
  from actor a, casting c, movie m
 where a.id = c.actorid
   and c.movieid = m.id
   and m.title = 'Casablanca'

2.顯示電影異型’Alien’ 的演員清單。

select a.name
  from actor a, casting c, movie m
 where a.id = c.actorid
   and c.movieid = m.id
   and m.title = 'Alien'

3.列出演員夏里遜福 ‘Harrison Ford’ 曾演出的電影。

select m.title
  from actor a, casting c, movie m
 where a.id = c.actorid
   and c.movieid = m.id
   and a.name = 'Harrison Ford'

4.列出演員夏里遜福 ‘Harrison Ford’ 曾演出的電影，但他不是第1主角。