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创建记录并提交会话

添加对象并通过会话持久化

创建记录并提交会话 是 CoddyKit 上的免费 Flask Academy 课时。这是第 1 节课，共 4 节。你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。这是 Flask Academy 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Flask Academy 课程共包含 4 节课。

本课时的部分内容尚未翻译，以英文显示。

The C in CRUD

Creating a record means turning incoming data into a new row in your table. In Flask-SQLAlchemy that flow runs through the session. ✨

Build the Object First

Start by making a fresh model instance with the values you want. Nothing has touched the database yet, it is just a Python object.

user = User(name="Ada", email="ada@mail.com")

Add It to the Session

Tell SQLAlchemy to track the new object by calling db.session.add(). This stages it, but it is still not saved.

db.session.add(user)

Commit to Save

Nothing is permanent until you call db.session.commit(). That flushes your changes and writes the row to the database.

db.session.commit()

The Id Appears After Commit

Once you commit, the database assigns a primary key. Read it back from user.id to confirm the row really exists.

db.session.commit()
print(user.id)

A Full Create Endpoint

Inside a POST view you read the body, build the object, add it, and commit. That is the whole create path in four lines.

data = request.get_json()
user = User(name=data["name"])
db.session.add(user)
db.session.commit()

Return 201 Created

A successful create should answer with status 201, the code that means a new resource was made on the server.

return jsonify(id=user.id), 201

Roll Back on Failure

If a commit fails, wrap it in try and call db.session.rollback() to undo the staged change and keep your session clean.

try:
    db.session.commit()
except Exception:
    db.session.rollback()

Add Many at Once

Need several rows? Stage them all with add_all(), then a single commit saves the whole batch together.

db.session.add_all([u1, u2, u3])
db.session.commit()

One Commit, One Transaction

Every add since the last commit is part of one transaction. They all succeed together, or none of them land if it fails.

Add Stages, Commit Saves

Remember the rhythm: build the object, add to stage it, then commit to save. Skipping commit means your data never persists.

Quick Check

You called add() but the row is missing from the table. What did you forget?

Recap: Creating Records

You build an object, add it, and commit to save, returning 201 and rolling back on errors. That is a solid create endpoint! 🎉

常见问题解答

「创建记录并提交会话」课时是免费的吗？

是的 — 「创建记录并提交会话」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Flask Academy 课程的其余内容，请升级到 CoddyKit PRO。 Flask Academy 课程共包含 4 节课。

「创建记录并提交会话」这节课中我会学到什么？

添加对象并通过会话持久化你通过在浏览器中直接运行的动手代码来练习 Flask Academy，全天候 AI 导师会在你学习这节课的过程中回答你的问题。

学习 Flask Academy 需要有经验吗？

无需任何先前经验。CoddyKit 上的 Flask Academy 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。这是第 1 节课，共 4 节。

「创建记录并提交会话」课时需要多长时间？

大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。

我能在这节 Flask Academy 课中编写并运行代码吗？

能。每节 Flask Academy 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。

此课程中的所有课时

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