MongoDB (Lesson 18 modifier)

3.4.3.2 modifier

For the MongoDB database, the modification of the data will involve the change of the content, the change of the structure (including the array), so when MongoDB is designed to provide a series of application of the modifier, then the "$set" as used before is a modifier.

1. $inc: Mainly for a numeric field, to increase the data content of a numeric field;

Syntax: {"$inc": {"member": Content}}

Example: reduction of 30 points for all students aged 19

MongoDB (Lesson 18 modifier)