MongoDB query expression

One, comparison operators

operator	operators that correspond to MySQL
$gt	>
$gte	>=
$in	In
$lt	<
$lte	<=
$ne	!=
$nin	Not in
$all	None of the corresponding items, the index group all cell matching have, use the same $in, $nin

Syntax format:
{column name: {$gt: Value}}
{column name: {$ne: Value}}
{column name: {$in: [Value1,value2,value3 ...]}}  
Note:

two, logical operators

operator	operators that correspond to MySQL
$or	Or
$and	and
$not	Not
$nor	No corresponding item, meaning "All listed conditions are not valid, true"

Syntax format:
{$and: [{columns: {$gte: value1}},{columns: {$gle: Value2}}]}

{$nor: [{columns: value1},{columns: value2},{columns: Value3} ...]}

three, element operator

name	Description
$exists	True if a column exists
$mod	Satisfies a certain remainder condition to be true
$type	Data is true for a type

Whether a column exists {column: {$exists: 1}}  #1表示存在
5 times times columns: {column: {$mod: [5,0]}}  #[5,0] represents a remainder of 5, with 0
type  {column: {$type: 2}}

type values from 1 to 19, and-1 and 127 corresponding data types check the official documentation:
https://docs.mongodb.com/manual/reference/operator/query/type/index.html

Four, JS operator (1)

name	Description
$where	The JS expression is true is true
$regex	Regular expression matches are true

$where and $regex is to convert all the Bson first to JSON object, and then for the JS engine query, memory consumption is more
suitable for a small number of data queries, generally do not recommend the

syntax format:
{$where: ' this. Column > Value1 && this. Column < value2 ... '}  

{column: {$regex:/pattern/<options>}}
for example: {
name: {$regex:  /acme.*corp/i, $nin: [' Acmeblahcorp ']}}
{name: {$regex:/acme.*corp/, $options: ' I ', $nin: [' Acmeblahcorp ']}
{name: {$regex: ' Acme.*corp ', $options: ' I ', $nin: [' Acmeblahcorp ']}}

Five, JS operator (2)

name	Description
$inc	Growth
$rename	renaming columns
$setOnInsert	Set the value of a field when Upsert
$set	Set a new value for a field
$unset	Deletes the specified column