以下有两个表，他们的结构完全相同，请通过SQL找出值不同的列。   Student_1   NAME AGE SCORE   peter 26 100   jack 25 96   daniel 26 48   bark 21 69   Student_2   NAME AGE SCORE   peter 26 89   jack 25 96   daniel 26 48   bark 21 69   方法一 -- NOT EXISTS：     复制代码 代码如下:     SELECT * FROM Student_1 S1 WHERE NOT EXISTS (SELECT * FROM Student_2 S2 WHERE S1.name = S2.name AND S1.age = S2.age AND S1.score = S2.score ) UNION ALL SELECT * FROM STUDENT_2 S2 WHERE NOT EXISTS (SELECT * FROM STUDENT_1 S1 WHERE S1.name = S2.name AND S1.age = S2.age AND S1.score = S2.score );   方法二 -- MINUS   复制代码 代码如下:     (SELECT * FROM Student_1 MINUS SELECT * FROM Student_2) UNION ALL (SELECT * FROM Student_2 MINUS SELECT * FROM Student_1)     方法三 -- HAVING GROUP BY   复制代码 代码如下:     SELECT DISTINCT name, age, score FROM ( SELECT * FROM Student_1 UNION ALL SELECT * FROM Student_2 )GROUP BY name, age, score HAVING COUNT(*)=1 ;