1、用一条SQL语句
查询出每门课都大于80分的学生姓名
SELECT DISTINCT NAME FROM t_score_tab WHERE NAME NOT IN (SELECT DISTINCT NAME FROM t_score_tab WHERE score <= 80)
2、查询两门或两门以上成绩都超过80分(含80)的学生姓名
SELECT NAME FROM t_score_tab WHERE score >= 80 GROUP BY NAME HAVING COUNT(1) >= 2