MongoDB opposite of $addToSet to '$removeFromS

问题:

I'm aware of the $addToSet method for MongoDB, but I can't find a remove equivalent anywhere in the docs.

What's the best way to achieve this? Trying to achieve something like the following:

obj = {
  name: 'object1
  tags: ['fus', 'ro', 'dah']
}

db.collection.update({name: 'object1'}, {$removeFromSet: { tags: 'dah'}});

回答1:

I think you are looking for $pull, which "removes all instances of a value from an existing array".

db.collection.update(
  {name: 'object1'}, 
  {$pull: { tags: 'dah'}});