使用事务在MongoDB (Mongoose)中创建链表

const mongoose = require('mongoose');
const { Schema } = mongoose;

// 定义链表节点的Schema
const nodeSchema = new Schema({
  value: Number,
  next: { type: Schema.Types.ObjectId, ref: 'Node' }
});

const Node = mongoose.model('Node', nodeSchema);

async function createLinkedList(values) {
  const session = await mongoose.startSession();
  session.startTransaction();

  try {
    let head;
    for (const value of values) {
      const newNode = new Node({ value });
      if (!head) {
        head = newNode;
      } else {
        let current = head;
        while (current.next) {
          current = current.next;
        }
        current.next = newNode._id;
      }
      await newNode.save({ session });
    }

    await session.commitTransaction();
    session.endSession();
    return head;
  } catch (error) {
    await session.abortTransaction();
    session.endSession();
    throw error;
  }
}

// 使用示例
(async () => {
  try {
    await mongoose.connect('mongodb://localhost:27017/test', { useNewUrlParser: true, useUnifiedTopology: true });
    const head = await createLinkedList([1, 2, 3, 4]);
    console.log('链表创建成功，头节点:', head);
  } catch (error) {
    console.error('创建链表时发生错误:', error);
  } finally {
    await mongoose.disconnect();
  }
})();