Flask 学生管理系统（单文件）

"""Flask 学生管理系统（单文件版）—— 站内原创示例代码

用途：一个可以直接运行的最小「学生管理系统」，包含列表、新增、删除三件事。
      适合作为「Flask 学生管理系统 / 毕业设计管理系统」类题目的起点，后续可再加
      登录、分页、成绩管理、导入导出等功能。
依赖：Flask（pip install flask）；数据库用 Python 自带的 sqlite3，无需安装。
运行：python flask-student-system.py，然后打开 http://127.0.0.1:5000
许可：MIT（开源拾遗原创，可自由使用与修改）
"""

import os
import sqlite3

from flask import Flask, redirect, render_template_string, request, url_for

DB_PATH = os.environ.get("DB_PATH", "students.db")

app = Flask(__name__)

PAGE = """
<!doctype html>
<html lang="zh-CN">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>学生管理系统</title>
  <style>
    body { font-family: system-ui, "Microsoft YaHei", sans-serif; max-width: 720px;
           margin: 48px auto; padding: 0 20px; color: #211d18; background: #f7f2e8; }
    h1 { font-size: 24px; }
    table { width: 100%; border-collapse: collapse; margin-top: 20px; }
    th, td { padding: 10px 8px; border-bottom: 1px solid #ddd3c2; text-align: left; }
    form.add { display: flex; gap: 8px; margin-top: 24px; flex-wrap: wrap; }
    input { padding: 8px 10px; border: 1px solid #ddd3c2; border-radius: 6px; }
    button { padding: 8px 14px; border: 0; border-radius: 6px; background: #b5482c;
             color: #fff; cursor: pointer; }
    button.danger { background: #7c7266; }
    .empty { color: #7c7266; margin-top: 20px; }
  </style>
</head>
<body>
  <h1>学生管理系统</h1>
  <p>共 {{ students|length }} 名学生</p>

  {% if students %}
  <table>
    <thead><tr><th>学号</th><th>姓名</th><th>专业</th><th>操作</th></tr></thead>
    <tbody>
      {% for s in students %}
      <tr>
        <td>{{ s["student_no"] }}</td>
        <td>{{ s["name"] }}</td>
        <td>{{ s["major"] }}</td>
        <td>
          <form method="post" action="{{ url_for('delete', student_id=s['id']) }}">
            <button class="danger" type="submit">删除</button>
          </form>
        </td>
      </tr>
      {% endfor %}
    </tbody>
  </table>
  {% else %}
  <p class="empty">还没有学生记录，先添加一条试试。</p>
  {% endif %}

  <form class="add" method="post" action="{{ url_for('add') }}">
    <input name="student_no" placeholder="学号" required>
    <input name="name" placeholder="姓名" required>
    <input name="major" placeholder="专业" required>
    <button type="submit">添加学生</button>
  </form>
</body>
</html>
"""


def get_db():
    conn = sqlite3.connect(DB_PATH)
    conn.row_factory = sqlite3.Row
    return conn


def init_db():
    with get_db() as conn:
        conn.execute(
            """CREATE TABLE IF NOT EXISTS students (
                   id INTEGER PRIMARY KEY AUTOINCREMENT,
                   student_no TEXT NOT NULL UNIQUE,
                   name TEXT NOT NULL,
                   major TEXT NOT NULL
               )"""
        )


@app.route("/")
def index():
    with get_db() as conn:
        students = conn.execute(
            "SELECT id, student_no, name, major FROM students ORDER BY id"
        ).fetchall()
    return render_template_string(PAGE, students=students)


@app.route("/add", methods=["POST"])
def add():
    student_no = (request.form.get("student_no") or "").strip()
    name = (request.form.get("name") or "").strip()
    major = (request.form.get("major") or "").strip()
    if student_no and name and major:
        with get_db() as conn:
            conn.execute(
                "INSERT OR IGNORE INTO students (student_no, name, major) VALUES (?, ?, ?)",
                (student_no, name, major),
            )
    return redirect(url_for("index"))


@app.route("/delete/<int:student_id>", methods=["POST"])
def delete(student_id):
    with get_db() as conn:
        conn.execute("DELETE FROM students WHERE id = ?", (student_id,))
    return redirect(url_for("index"))


@app.route("/health")
def health():
    return {"status": "ok", "db": DB_PATH}


init_db()

if __name__ == "__main__":
    app.run(host="127.0.0.1", port=5000, debug=False)