内容摘要:复制SELECT*FROMSTUDENT,(SELECT*FROMSCORE)assc; SELECT(SELECTAVG(degree)FROMSCORE),snameFROM

复制SELECT * FROM STUDENT,查询
(SELECT * FROM SCORE) as sc; SELECT (SELECTAVG(degree) FROM SCORE), sname FROM STUDENT; SELECT * FROM STUDENT WHERE EXISTS (SELECT A FROM SCORE WHERE SCORE.sno = STUDENT.sno); 1.2.3.