右外连接:RIGHT OUTER JOIN 右边表中即使不满足连接条件的也会显示出来
6.SELECT *FROM stu,stuscore WHERE stu.id=stuscore.ID; 7.SELECT stu.*,stuscore.*FROM stu LEFT JOIN stuscore ON stu.id=stuscore.id; 8.SELECT stu.*,stuscore.*FROM stu RIGHT JOIN stuscore ON stu.id=stuscore.id; 9.SELECT stu.id,stu.`name`,stuscore.score,stuscore.`subject` FROM ...