SQL题目

 有如下数据表

create table test (NAME varchar(20) not null, HOBBY varchar(20) not null);  
 insert into test values('Adam','basketball');
 insert into test values('Bill','basketball');
 insert into test values('Bill','football');
 insert into test values('Cyper','basketball');
 insert into test values('Cyper','badminton');
 insert into test values('David','basketball');
 insert into test values('David','badminton');
 insert into test values('David','table tennis');

 

使用SQL语句查出hobby即包含basketball,又包含badminton的name所在的行：

即第5， 6 ，7 ，8行

 

 

我想了几种SQL语句。不知道还没有有别的。

--(1)with
WITH
  NAME_MATCHES AS
     (SELECT NAME
        FROM TEST
        WHERE HOBBY IN ('basketball', 'badminton')
        GROUP BY NAME
        HAVING COUNT(NAME) = 2)
SELECT T.*
  FROM TEST AS T, NAME_MATCHES AS NM
  WHERE T.NAME = NM.NAME;

--(2)exists and exists
SELECT *
  FROM TEST AS T1
  WHERE EXISTS (SELECT *
          FROM TEST AS T2
          WHERE T2.NAME = T1.NAME AND HOBBY = 'basketball')
    AND EXISTS (SELECT *
          FROM TEST AS T3
          WHERE T3.NAME = T1.NAME AND HOBBY = 'badminton');

--(3)self join
SELECT T1.*
  FROM TEST AS T1, TEST AS T2, TEST AS T3
  WHERE T1.NAME = T2.NAME AND T1.NAME = T3.NAME AND T2.HOBBY = 'basketball'
    AND T3.HOBBY = 'badminton';

 

第1种是我目前采纳的，稍微有点长

第3种最简单，可是扩展性不好，当hobby增多时，参数不好处理。

 

欢迎讨论（各种数据库都可以）