mongodb usage of find

Symbol Meaning Test Example:

$lt小于 {'age':{"$lt":20}}

Lt is greater than $ { 'age': { "$ gt": 20}}

Less lt $ { 'age': { "$ lte": 20}}

$ Lt than or equal to { 'age': { "$ gte": 20}}

NE is not equal to $ { 'age': { "$ ne": 20}}

In in the range of $ { 'age': { "$ in": [20,30]}}

Nin in the range of $ { 'age': { "$ nin": [20,30]}}

Advanced Usage:

REGEX matches regular $ { 'name': { "$ regex": '. ^ M *'}} name begin to M

$ Where high-level criteria query { '$ where': 'obj.age_count == obj.book_count'} is equal to the age of the book Statistics

$ Mod digital mode operation { 'age': { '$ mod': [5,3]}} supplier age is 5, the remainder of age 3