RESTful接口更新情况下，如何解决int值为空的问题？

from flask import Flask, request, jsonify

app = Flask(__name__)

@app.route('/update', methods=['PUT'])
def update_resource():
    data = request.get_json()
    user_id = data.get('user_id')
    
    if user_id is None:
        return jsonify({"error": "user_id is required"}), 400
    
    try:
        user_id = int(user_id)
    except ValueError:
        return jsonify({"error": "user_id must be an integer"}), 400
    
    # 继续处理更新逻辑
    return jsonify({"message": "Resource updated successfully"}), 200

if __name__ == '__main__':
    app.run(debug=True)

@app.route('/update', methods=['PUT'])
def update_resource():
    data = request.get_json()
    user_id = data.get('user_id', 0)  # 默认值为0
    
    try:
        user_id = int(user_id)
    except ValueError:
        return jsonify({"error": "user_id must be an integer"}), 400
    
    # 继续处理更新逻辑
    return jsonify({"message": "Resource updated successfully"}), 200

from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    age = db.Column(db.Integer, nullable=True)

@app.route('/update', methods=['PUT'])
def update_user():
    data = request.get_json()
    user_id = data.get('user_id')
    age = data.get('age')
    
    if user_id is None:
        return jsonify({"error": "user_id is required"}), 400
    
    user = User.query.get(user_id)
    if user is None:
        return jsonify({"error": "User not found"}), 404
    
    user.age = age
    
    try:
        db.session.commit()
    except Exception as e:
        db.session.rollback()
        return jsonify({"error": str(e)}), 500
    
    return jsonify({"message": "User updated successfully"}), 200