Mongodb entry-7 query 2

Mongodb entry-7 query 2 array query $ all $ in $ all the elements of all Given Queries must be included in the array $ in. The following two codes can be viewed as long as the given query elements are included in the array.: [html] db. phone. find () {_ id: ObjectId (5198e20220c9b0dc40419385), num: [519, 3]} {_ id: ObjectId (

Mongodb entry-7 query 2 array query $ all $ in $ all the elements of all Given Queries must be included in the array $ in. The following two codes can be viewed as long as the given query elements are included in the array.: [html] db. phone. find () {_ id: ObjectId (5198e20220c9b0dc40419385), num: [1, 2, 3]} {_ id: ObjectId (519)

Mongodb entry-7 query 2

Array query $ all $ in

The $ all array must contain all the elements of the given query.

The $ in array can contain the given query element.

See the following two codes:

[Html]

> Db. phone. find ()

{"_ Id": ObjectId ("5198e20220c9b0dc40419385"), "num": [1, 2, 3]}

{"_ Id": ObjectId ("5198e21820c9b0dc40419386"), "num": [4, 2, 3]}

{"_ Id": ObjectId ("5198e22120c9b0dc40419387"), "num": [1, 2, 5]}

> Db. phone. find ({num: {$ all: [1, 2]})

{"_ Id": ObjectId ("5198e20220c9b0dc40419385"), "num": [1, 2, 3]}

{"_ Id": ObjectId ("5198e22120c9b0dc40419387"), "num": [1, 2, 5]}

> Db. phone. find ({num: {$ all: []}) ---> no data including

> Db. phone. find ({num: {$ in: []}) ---> contains 1 or 4 Data

{"_ Id": ObjectId ("5198e20220c9b0dc40419385"), "num": [1, 2, 3]}

{"_ Id": ObjectId ("5198e21820c9b0dc40419386"), "num": [4, 2, 3]}

{"_ Id": ObjectId ("5198e22120c9b0dc40419387"), "num": [1, 2, 5]}

$ Exists: search for documents containing this field

A piece of code is as follows:

[Html]

> Db. phone. find ()

{"_ Id": ObjectId ("5198e20220c9b0dc40419385"), "num": [1, 2, 3]}

{"_ Id": ObjectId ("5198e21820c9b0dc40419386"), "num": [4, 2, 3]}

{"_ Id": ObjectId ("5198e22120c9b0dc40419387"), "num": [1, 2, 5]}

{"_ Id": ObjectId ("5198e51a20c9b0dc40419388"), "state": 1}

> Db. phone. find ({state: {$ exists: 1}) --->

{"_ Id": ObjectId ("5198e51a20c9b0dc40419388"), "state": 1}

> Db. phone. find ({state: {$ exists: 0}) ---> document without the state field

{"_ Id": ObjectId ("5198e20220c9b0dc40419385"), "num": [1, 2, 3]}

{"_ Id": ObjectId ("5198e21820c9b0dc40419386"), "num": [4, 2, 3]}

{"_ Id": ObjectId ("5198e22120c9b0dc40419387"), "num": [1, 2, 5]}

$ Mod modulo operation

For example, we can perform some modulo operations when taking some data, such as the following documents with an age model of 3 or more:

[Html]

> Db. user. find ()

{"_ Id": ObjectId ("5198c286c686eb50e2c843b2"), "name": "user0", "age": 0}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b3"), "name": "user1", "age": 1}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b4"), "name": "user2", "age": 2}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b5"), "name": "user3", "age": 3}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b6"), "name": "user4", "age": 4}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b7"), "name": "user5", "age": 5}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b8"), "name": "user6", "age": 6}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b9"), "name": "user7", "age": 7}

{"_ Id": ObjectId ("5198c286c686eb50e2c843ba"), "name": "user8", "age": 8}

{"_ Id": ObjectId ("5198c286c686eb50e2c843bb"), "name": "user9", "age": 9}

{"_ Id": ObjectId ("5198c286c686eb50e2c843bc"), "name": "user10", "age": 10}

{"_ Id": ObjectId ("5198c3cac686eb50e2c843bd"), "name": "user0", "age": 20}

> Db. user. find ({age: {$ mod: [3, 1]})

{"_ Id": ObjectId ("5198c286c686eb50e2c843b3"), "name": "user1", "age": 1}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b6"), "name": "user4", "age": 4}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b9"), "name": "user7", "age": 7}

{"_ Id": ObjectId ("5198c286c686eb50e2c843bc"), "name": "user10", "age": 10}

The statement db. user. find ("this. age % 3 = 1") can also be used to achieve the above effect, but it is not recommended.

$ Ne not equal is not equal

Search for users whose age is not equal to 0:

[Html]

> Db. user. find ()

{"_ Id": ObjectId ("5198c286c686eb50e2c843b2"), "name": "user0", "age": 0}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b3"), "name": "user1", "age": 1}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b4"), "name": "user2", "age": 2}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b5"), "name": "user3", "age": 3}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b6"), "name": "user4", "age": 4}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b7"), "name": "user5", "age": 5}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b8"), "name": "user6", "age": 6}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b9"), "name": "user7", "age": 7}

{"_ Id": ObjectId ("5198c286c686eb50e2c843ba"), "name": "user8", "age": 8}

{"_ Id": ObjectId ("5198c286c686eb50e2c843bb"), "name": "user9", "age": 9}

{"_ Id": ObjectId ("5198c286c686eb50e2c843bc"), "name": "user10", "age": 10}

{"_ Id": ObjectId ("5198c3cac686eb50e2c843bd"), "name": "user0", "age": 20}

> Db. user. find ({age: {$ ne: 0 }})

{"_ Id": ObjectId ("5198c286c686eb50e2c843b3"), "name": "user1", "age": 1}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b4"), "name": "user2", "age": 2}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b5"), "name": "user3", "age": 3}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b6"), "name": "user4", "age": 4}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b7"), "name": "user5", "age": 5}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b8"), "name": "user6", "age": 6}

{"_ Id": ObjectId ("5198c286c686eb50e2c843b9"), "name": "user7", "age": 7}

{"_ Id": ObjectId ("5198c286c686eb50e2c843ba"), "name": "user8", "age": 8}

{"_ Id": ObjectId ("5198c286c686eb50e2c843bb"), "name": "user9", "age": 9}

{"_ Id": ObjectId ("5198c286c686eb50e2c843bc"), "name": "user10", "age": 10}

{"_ Id": ObjectId ("5198c3cac686eb50e2c843bd"), "name": "user0", "age": 20}

Some people refer to the method starting with $ as a magic method. It doesn't matter. This method is generally not in json, that is, it is generally used in, this is also the value of a field. it will be exposed later.