编辑代码

CREATE DATABASE test;
use test;
CREATE TABLE S (
	SX int,
	SNAME varchar(255)
);
CREATE TABLE SC (
	SX int,
	CX int
);
CREATE TABLE C (
	CX int,
	n varchar(255)
	
);
INSERT INTO S VALUES (1, '手动');
INSERT INTO S VALUES (2, '法国');
INSERT INTO S VALUES (3, '是到付');
INSERT INTO S VALUES (4, '十大');
INSERT INTO S VALUES (5, '撒大苏打');
INSERT INTO S VALUES (6, '大师大卫');

INSERT INTO SC VALUES (1, 1);
INSERT INTO SC VALUES (2, 2);
INSERT INTO SC VALUES (3, 1);
INSERT INTO SC VALUES (4, 3);
INSERT INTO SC VALUES (5, 2);
INSERT INTO SC VALUES (6, 2);

INSERT INTO C VALUES (1, 'MATHS');
INSERT INTO C VALUES (2, 'PE');
INSERT INTO C VALUES (3, 'EE');

SELECT S.SX,S.SNAME FROM S,SC,C
WHERE S.SX=SC.SX
AND C.CX=SC.CX
AND n='MATHS'