题目:38.成绩数据库现有学生成绩数据库school.db,包含表结构:CREATE TABLE scores (id INT, name TEXT, math INT, class TEXT)请补全代码完成以下功能:1.修改指定班级学生的数学成绩2.统计各班数学成绩>120分的学生人数3.输出格式化结果(本题无需运行通过,写入代码即可)import sqlite3conn = sqlite3.connect('school.db')cursor = conn.cursor()\# 任务1:修改成绩(示例:将1班张三数学成绩改为135)update_sql = "UPDATE scores SET math = ? WHERE class = ? AND name = ?"cursor.execute(update_sql, (135, '1班', '张三')) ① \# 任务2:统计各班数学120高分人数cursor.execute("SELECT class FROM scores WHERE math > 120")results = ② class_counts = {}for row in results: class_name = row[0] if class_name in class_counts: ③ else: class_counts[class_name] = 1\# 任务3:格式化输出结果print("各班数学高分统计:")for class_name, count in ④ : print(f"{class_name.ljust(6)}: {'★'*count}")cursor.close() ⑤