打印该级别的学生和平均年龄,除JR以外的所有级别。我想写mysql查询
CREATE TABLE STUDENT (
sid NUMERIC(6) NOT NULL,
sname VARCHAR(15),
major VARCHAR(20),
level VARCHAR(2),
sage NUMERIC(2) NOT NULL,
PRIMARY KEY (sid)
);
INSERT INTO STUDENT (sid, sname, major, level, sage) values (1,'JOHN','EE','FR' ,18);
INSERT INTO STUDENT (sid, sname, major, level, sage) values (2,'TIM','EE','FR',19);
INSERT INTO STUDENT (sid, sname, major, level, sage) values (3,'RICHARD','EE','SO',20);
INSERT INTO STUDENT (sid, sname, major, level, sage) values (4,'EDWARD','EE','SO',21);
INSERT INTO STUDENT (sid, sname, major, level, sage) values (5,'ALBER','CS','JR',22);
INSERT INTO STUDENT (sid, sname, major, level, sage) values (6,'MARY','EE','JR',22);
INSERT INTO STUDENT (sid, sname, major, level, sage) values (7,'JACK','EE','SR',23);
INSERT INTO STUDENT (sid, sname, major, level, sage) values (8,'JULIAN','EE','SR',22);
INSERT INTO STUDENT (sid, sname, major, level, sage) values (9,'SAM','EE','SR',24);
INSERT INTO STUDENT (sid, sname, major, level, sage) values (10,'RAM','CS','SR',23);
INSERT INTO STUDENT (sid, sname, major, level, sage) values (11,'RICK','EE','SR',24);
新加坡国立大学医院嗯。你写它,然后回来一个具体的问题。 – simchona 2012-04-17 18:07:46
你应该真的显示你已经尝试过 – wickedone 2012-04-17 18:13:39