Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
I’m a mongodb noob trying to learn mongodb…
I’m just tying to understand what this line is saying in english…
{ $project : { _id : { $substr : ["$_id",0,1] } } }
can someone translate?
It says that in the response to a query being projected through this expression, the
_idfield of each object should be replaced by only the first character of its actual value. It’s part of the aggregation framework, documented here.