mongodb wildcard match all values for specific key

问题:

This question already has an answer here:

• Check that Field Exists with MongoDB 4 answers

I am trying to figure out how to match a key and return all the values for that key. Is it possible to give the value as a wildcard? I want to return everything for that specific key using wildcard on the value.

db.collection.find({"key" :"*"})

Also I was hoping this would return the entire collection as well that had the key with the wildcard value match as well.

回答1:

You may be looking for something like this:

db.collection.find({"key": {$exists: true}})

This will return all documents in the collection where the key "key" is present. The entire document is returned.

回答2:

Yes:

db.collection.distinct("key")