Consider the following document from the products collection:
What does the following query using $elemMatch return? db.products.find( { product_code: "345678" }, { variations: { $elemMatch: { size: ^L^ } } } )
To add a new user and enable authentication in MongoDB, which of the following steps need be executed?
Consider that you have a collection called population which has fields state and city. Which of the following query will calculate the population grouped by state and city?
Dada una coleccion, cuales devuelve con la siguiente query
db.coleccion.find({nombre:"ruben",apellido:"gomez"},{nombre:l,apellido:l,aficion:l});