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语句查出哪些人即会玩basketball又会玩badminton,找出这样的name-hobby组合。(这样表达如何?)
即第5, 6 ,7 ,8行
select * from testsql WHERE HOBBY='basketball' and NAME in ( select NAME from testsql where HOBBY ='badminton' )