用一个merge语句表达将student表中的数据同步到newstudent表中；在student中插入一行数据，再同步到newstudent；更改新插入同学的出生日期后再同步到newstudent；删除新学生记录后同步到newstudent四个步骤的全部同步数据操作

1. 将student表中的数据同步到newstudent表中：

    MERGE INTO newstudent ns
    USING student s ON (ns.id = s.id)
    WHEN MATCHED THEN
        UPDATE SET
            ns.name = s.name,
            ns.age = s.age,
            ns.gender = s.gender,
            ns.birthday = s.birthday
    WHEN NOT MATCHED THEN
        INSERT (ns.id, ns.name, ns.age, ns.gender, ns.birthday)
        VALUES (s.id, s.name, s.age, s.gender, s.birthday);

2. 在student中插入一行数据，再同步到newstudent：

    INSERT INTO student (id, name, age, gender, birthday)
    VALUES (6, 'Tom', 20, 'Male', '2000-01-01');

    MERGE INTO newstudent ns
    USING (SELECT id, name, age, gender, birthday FROM student WHERE id = 6) s
    ON (ns.id = s.id)
    WHEN MATCHED THEN
        UPDATE SET
            ns.name = s.name,
            ns.age = s.age,
            ns.gender = s.gender,
            ns.birthday = s.birthday
    WHEN NOT MATCHED THEN
        INSERT (ns.id, ns.name, ns.age, ns.gender, ns.birthday)
        VALUES (s.id, s.name, s.age, s.gender, s.birthday);

3. 更改新插入同学的出生日期后再同步到newstudent：

    UPDATE student SET birthday = '2000-02-01' WHERE id = 6;

    MERGE INTO newstudent ns
    USING (SELECT id, name, age, gender, birthday FROM student WHERE id = 6) s
    ON (ns.id = s.id)
    WHEN MATCHED THEN
        UPDATE SET
            ns.name = s.name,
            ns.age = s.age,
            ns.gender = s.gender,
            ns.birthday = s.birthday
    WHEN NOT MATCHED THEN
        INSERT (ns.id, ns.name, ns.age, ns.gender, ns.birthday)
        VALUES (s.id, s.name, s.age, s.gender, s.birthday);

4. 删除新学生记录后同步到newstudent：

    DELETE FROM student WHERE id = 6;

    DELETE FROM newstudent WHERE id = 6;