Student Marksheet Database Project

परिचय

Schema

CREATE TABLE students (roll_no INT PRIMARY KEY, name VARCHAR(50));
CREATE TABLE marks (roll_no INT, subject VARCHAR(20), score INT,
  PRIMARY KEY(roll_no, subject),
  FOREIGN KEY(roll_no) REFERENCES students(roll_no));

Result Query

SELECT s.name, SUM(m.score) AS total, ROUND(AVG(m.score),1) AS pct
FROM students s JOIN marks m ON s.roll_no=m.roll_no
GROUP BY s.name;

सारांश

• marks composite key (roll_no + subject) use करता है।
• JOIN + GROUP BY हर student का total और percentage बनाता है।