使用oracle数据库，模拟生成成绩表,要求每个学生都有3科成绩,成绩随机.每个班的每个学科自定义匹配一个老师ID。各老师的工作量应相等。（可以使用游标或其它你认为合适的方式），已知有6个老师，一个学科两个老师，每个老师执教两个班级。

为了实现每个学生都有3科成绩，每个班的每个学科自定义匹配一个老师ID，并且各老师的工作量相等，你可以按照以下步骤进行操作：

1. 创建相关表结构：

CREATE TABLE Students (
    student_id INT PRIMARY KEY,
    student_name VARCHAR(50)
);

CREATE TABLE Subjects (
    subject_id INT PRIMARY KEY,
    subject_name VARCHAR(50)
);

CREATE TABLE Teachers (
    teacher_id INT PRIMARY KEY,
    teacher_name VARCHAR(50)
);

CREATE TABLE Classes (
    class_id INT PRIMARY KEY,
    class_name VARCHAR(50),
    teacher_id INT,
    FOREIGN KEY (teacher_id) REFERENCES Teachers (teacher_id)
);

CREATE TABLE Score (
    student_id INT,
    subject_id INT,
    score INT,
    class_id INT,
    FOREIGN KEY (student_id) REFERENCES Students (student_id),
    FOREIGN KEY (subject_id) REFERENCES Subjects (subject_id),
    FOREIGN KEY (class_id) REFERENCES Classes (class_id)
);

2. 插入学生、科目、老师和班级数据：

-- 插入学生数据
INSERT INTO Students (student_id, student_name)
SELECT LEVEL, 'Student ' || LEVEL
FROM DUAL
CONNECT BY LEVEL <= 50;

-- 插入科目数据
INSERT INTO Subjects (subject_id, subject_name)
SELECT LEVEL, 'Subject ' || LEVEL
FROM DUAL
CONNECT BY LEVEL <= 3;

-- 插入老师数据
INSERT INTO Teachers (teacher_id, teacher_name)
SELECT LEVEL, 'Teacher ' || LEVEL
FROM DUAL
CONNECT BY LEVEL <= 6;

-- 插入班级数据
INSERT INTO Classes (class_id, class_name, teacher_id)
SELECT LEVEL, 'Class ' || LEVEL, CEIL(LEVEL/2)
FROM DUAL
CONNECT BY LEVEL <= 4;

3. 生成成绩数据：

DECLARE
    student_count INT := 50; -- 学生数量
    subject_count INT := 3; -- 科目数量
    teacher_count INT := 6; -- 老师数量
BEGIN
    FOR i IN 1..student_count LOOP
        FOR j IN 1..subject_count LOOP
            -- 获取当前学科对应的两个老师ID
            DECLARE
                teacher_id1 INT;
                teacher_id2 INT;
            BEGIN
                SELECT teacher_id
                INTO teacher_id1
                FROM Classes
                WHERE class_id = CEIL(j/2);

                SELECT teacher_id
                INTO teacher_id2
                FROM Classes
                WHERE class_id = CEIL(subject_count/2) + CEIL(j/2);
            END;

            -- 随机选取一个老师ID
            DECLARE
                selected_teacher_id INT;
            BEGIN
                IF DBMS_RANDOM.VALUE(0, 1) >= 0.5 THEN
                    selected_teacher_id := teacher_id1;
                ELSE
                    selected_teacher_id := teacher_id2;
                END IF;
            END;

            -- 插入成绩记录
            INSERT INTO Score (student_id, subject_id, score, class_id)
            VALUES (i, j, DBMS_RANDOM.VALUE(50, 100), selected_teacher_id);
        END LOOP;
    END LOOP;
END;
/

上述代码中，首先创建了学生、科目、老师和班级的表结构。然后插入了相应的数据。最后使用PL/SQL生成成绩数据，其中通过查询班级表获取每个学科对应的两个老师ID，然后根据随机值选取一个老师ID为该学科的成绩记录插入相应的班级。

请注意，上述代码中假设了每个学科有两个老师执教两个班级，你可以根据实际情况进行相应的调整。