在Mongoose中向多对多关系添加文档(MongoDB)

const mongoose = require('mongoose');

const userSchema = new mongoose.Schema({
  name: String,
  // 其他字段...
});

const groupSchema = new mongoose.Schema({
  name: String,
  // 其他字段...
});

const User = mongoose.model('User', userSchema);
const Group = mongoose.model('Group', groupSchema);

const membershipSchema = new mongoose.Schema({
  user: { type: mongoose.Schema.Types.ObjectId, ref: 'User' },
  group: { type: mongoose.Schema.Types.ObjectId, ref: 'Group' },
  // 其他字段...
});

const Membership = mongoose.model('Membership', membershipSchema);

const user1 = new User({ name: 'User1' });
const group1 = new Group({ name: 'Group1' });

user1.save();
group1.save();

const membership = new Membership({ user: user1._id, group: group1._id });
membership.save();