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Databases Mongo Basics Working With Collections Querying Collections

Posted by Alejandro Ochoa
Alejandro Ochoa
Courses Plus Student 10,671 Points

Question Using Or

in minute 4:09 as he is finishing demonstrating the or operator, he wrote the following:

db.posts.find({$or: [{title: "Parenting 101"}, {title: "My Awesome Recipe!"}]},{}) my question is what is the very last {} just before he closes the parenthesis mean...??

1 Answer

Jose Vaca Cipres
Jose Vaca Cipres
10,724 Points
Jose Vaca Cipres
Jose Vaca Cipres
10,724 Points

The last bracket means a "projection". The projection has the following description: Specifies the fields to return in the documents that match the query filter. To return all fields in the matching documents, omit this parameter. For details, see Projection.

It is optional and how you can see, he did not put until minute 4:12. Also, you can check the documention about of that in https://docs.mongodb.com/v3.2/reference/method/db.collection.find/#definition

Pd: Sorry for my bad English! Have a nice day! :D