Mongoid query for array field

问题:

I have a category field of type Array in Mongoid.

Ex. category: ["val1","val2","val3"]

Now I want to query this Model with `category: ["val1","val2"] such that it returns me the merge of

Model.where(category: "val1") and Model.where(category: "val2")

I can do it individually for each element of the array but that will be slow I guess because for every individual element it will search all the documents.

I also tried Model.all_of({category: "val1"},{category: "val2"}).all but that is not working.

How should I do this?

回答1:

In mongoid, there is '$in' operator. So you can do this :

Model.where(category: { '$in': ['val1', 'val2'] })

回答2:

You can use Criteria all_in to make it simpler:

Model.all_in(category: ['val1','val2'])

回答3:

This worked

Model.where(:category.in => ['val1','val2'])

From Mongo Docs