MongooseJS没有正确保存数组

Question

我想,我在使用mongoosejs时遇到了麻烦.我试图保持一个特定大小为2的对象数组.当调用此函数时,它会向数组添加一个项目,并在必要时将其缩小.但是,当我保存数组时,大小不会减少到2.遵循代码和注释.感谢您的任何帮助,您可以提供.

 user.location.push(req.body);  //Add a new object to the array.

    if(user.location.length > 2)  //If the array is larger than 2
      user.location.splice(0,1);   //Remove the first item

    console.log(user.location);  //This outputs exactly what I would expect.

    user.save(function(err, updatedUser){
      if(err)
        next(new Error('Could not save the updated user.'));
      else { 
        res.send(updatedUser);  //This outputs the array as if it was never spliced with a size greater than 2.
      }
    });

Answer 1

因为您location: []在模式中定义,所以Mongoose会对该字段进行处理,Mixed这意味着您必须在更改时通知Mongoose.请参阅此处的文档.

将更新的代码更改user.location为:

if(user.location.length > 2) {
  user.location.splice(0,1);
  user.markModified('location');
}