Mongdb learning notes

1.NoSQL Characteristics

It's a non relational database , Storage in document form
characteristic ： The document database stores data in the form of documents ,BSON Format , similar JSON, It's a collection of data items . Each data item has a name and a corresponding value , Values can be simple data types , Such as a string / Numbers / Date, etc. . It can also be a complex type .
== advantage ：== Data structure requirements are not strict , Variable table structure , You don't need to predefine the table structure like a relational database
== shortcoming ：== Poor query performance , Lack of uniform query syntax
Application scenarios ： journal ,web Application etc.

Start command ：

--dbpath：  Specify the directory where the data file is stored 
--logpath： Specify log files , Note that the specified file is not a directory 
--logappend： Log by appending 
--port： Designated port , The default is 27017
--bind_ip： Binding services IP, If bound 127.0.0.1, Can only be accessed locally , Default to local address 

mongod --dbpath D:\MongDB\data\db

3. Safety certification

Create administrator account

# To set the administrator user name and password, you need to switch to admin library 
use admin
# Create administrator 
db.createUser({
    user:"fox",pwd:"fox",roles:["root"]})
# View all user information 
show users
# Delete user 
db.dropUser("fox")
# Log in with the user , Default to admin library 
mongo -ufox -pfox --authenticationDatabase=admin

4.MongoDB The document operation

1. Inserted into the document

2. Query the document

db.collection.find(query,projection)
db.collection.findOne(query,projection)
*query: Optional , Use the query operator to specify the query criteria
*projection: Optional , Use the projection operator to specify the returned key
Query cross reference table

example ：

example ：

Check stock out users All data in

db.users.find()

Conditions of the query , Inquire about user The value is root Of

db.users.find({user:“root”})

Query a value greater than a certain number

db.users.find({age:{$gt:60}})

Find the first

db.users.findOne()

Sort & Pagination
stay MongoDB Use in sort() Method to sort the data

# Specify by collection （favCount） Return in descending order   -1 Representation of descending order     Expressing ascending order 
favCount  type All field names 
db.books.find({
    type:"travel"}).sort({
    favCount:-1})

Paging query ： adopt skip and limit To achieve ,skip Indicates the specified number of skipped records ,limit It means to limit the number of returned results
example ：

db.books.find().skip().limit(5)

3. Update the document

It can be used update Command to update the specified data , The command format is as follows ：

db.collection.update(query,update,options)
db.collection.updateOne(query,update,options) // Update individual documents   amount to  multi The attribute is true
db.collection.updateMany(query,update,options) // Update multiple documents 
db.collection.replaceOne(query,update,options) // Replace a single document 
#  Attribute interpretation ：
# query : Describe the updated query criteria 
# update: Describe the updated actions and new content 
# options： Describe the options for updating 
# - upsert： Optional , If it doesn't exist update The record of , Whether to insert a new record . Default false, Do not insert 
  - multi： Optional , Whether to update all the multiple records queried by criteria . Default false, Update only the first record found 
  - writeConcern: Optional , Determine how many nodes a write operation falls on before it is considered successful （ Similar to transaction operation ）

update The operators are as follows ：

example ：

db.books.update({
    type:"novel"},{
    $Set:{
    publishedDate:new Date()}},{
    "multi":true})

Be careful ： If udate The update description in the command does not contain any operators , that MongoDB It will realize the of documents replace semantics

 example ：
db.books.update({
    type:"novel"},{
    age:"1"})
 Will find type by novel The data of , Then its contents are completely replaced , Only  age:1

findAndModify command ：

Find and update , Only single documents can be operated , Cannot operate on multiple documents
Format ：

 example ： increase new :true, The updated value will be returned ,false Return the value before update 
db.books.findAndModify({
    query:{
    },update:{
    }},new :true)

findOneAndUpdate: Update a single document and return to the pre update （ Or after update ） Documents
findOneAndReplace: Replace a single document and return to the previous （ Or after replacement ） Documents

4. Delete the document

remove command
example ：

 example ：
db.books.remove({
    age:28}) // Delete age be equal to 28  The record of 
db.books.remove({
    age:{
    $lt:25}})  // Delete age Less than 25 The record of 
db.books.remove({
    }) // Delete all records 

If there are more than one qualified , But only delete the first , You need to make justOne Parameters of , The format is as follows
example ：

 example ：
db.books.remove({
    age:28},true) 

delete command ：
Official recommendation deleteOne() and deleteMany() Method delete stable , The syntax is as follows ：

 example ：
db.books.deleteMany({
    }) // Delete all documents under the collection 
db.books.deleteMany({
    type:"novel"})  // Delete all data with specified conditions 
db.books.deleteOne({
    type:"novel"})  // Specify the data of the condition , Delete only the first 

If you need to return the deleted document
command ：findOneAndDelete

 example ：
db.books.findOneAndDelete({
    type:"novel"}) // Delete all documents under the collection 

MongoDB Integrate SpringBoot

1 Introduce dependencies

   <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-mongodb</artifactId>
   </dependency>

2.yml File configuration

spring:
  data:
    mongodb:
      uri: mongodb://fox:[email protected]:27017/user?authSource=admin
      #uri Equivalent to the following configuration 
# database: user
# host: 127.0.0.1
# port: 27017
# username: fox
# password: fox
# authentication-database: admin

3. Inject bean

 @Autowired
    MongoTemplate mongoTemplate;

4. Use

1. Add, delete and change the set

 // Operations on collections 
    @RequestMapping("/test1")
    public void ok(){
    
        // Determine whether a set exists 
        boolean flag = mongoTemplate.collectionExists("emp");
        if(flag){
    
            // Delete the collection 
            mongoTemplate.dropCollection("emp");
        }
        // Create set 
        MongoCollection<Document> emp1 = mongoTemplate.createCollection("emp");
    }

    // Querying documents 
    @RequestMapping("/test2")
    public void test2(){
    
        //============= Common query ====================
        // Find all documents 
        List<User> list = mongoTemplate.findAll(User.class);
        // according to ID Inquire about 
        User us = mongoTemplate.findById(1, User.class);
        // The query result is multiple , Return to the first one 
        User u = mongoTemplate.findOne(new Query(), User.class);

        //============= Conditions of the query =====================
        // Build query criteria 
        Query query1 = new Query(Criteria.where("salary").gte(8000));
        Query query2 = new Query(Criteria.where("salary").gte(8000).lt(10000));
        Query query3 = new Query(Criteria.where("name").regex(" Zhang ")); // Fuzzy matching 


        //============== Multiconditional query ===================
        Criteria criteria1 = new Criteria();
        Criteria criteria2 = new Criteria();
        //and Conditions 
        criteria1.andOperator(Criteria.where("age").gt(25),Criteria.where("salary").gt(8000));
        //or Conditions 
        criteria1.orOperator(Criteria.where("age").gt(25),Criteria.where("salary").gt(8000));

        Query query = new Query(criteria1);

        //sort Sort 
        query.with(Sort.by(Sort.Order.desc("salary")));
        // Pagination 
        query.skip(1).limit(10);
        // Find all documents , The third parameter is the set name 
        List<User> list = mongoTemplate.findAll(query, TestUser.class, "test2");
    }

    // Document update operation 
    @RequestMapping("/test3")
    public void test3(){
    
        // First, find out what you want to modify 
        Query query = new Query(Criteria.where("salary").gte(8000));
        User u = mongoTemplate.findOne(query, User.class);
        Update update = new Update();
        update.set("name"," Zhang San ");
        //UpdateResult（）
        //UpdateFirst（） Update the first record that meets the condition 
        //UpdateMulti（） Update all records that meet the conditions 
        //upsert()  If there are no qualified records, insert data 
        UpdateResult updateResult = mongoTemplate.upsert(query, update, User.class);

        // Return the number of modified records 
        System.out.println(updateResult.getModifiedCount());
    }

2. Inquire about
Use bson Query as query criteria

//1. Construct query conditions 
	 Bson filters = Filters.and(
                Filters.eq("deviceId", warningEvent.getDeviceId()),
                Filters.gte("date", strTime.getTime()),
                Filters.lte("date", endTime.getTime()),
                Filters.eq("lastUpdateTime", DateUtil.format(updateDate, "yyyy-MM-dd HH:mm"))
        );
    //2. Specify field sort , Ascending or descending 
     Bson sort = Sorts.ascending("name");
     // Bson sort = Sorts.descending("name");
     //3. Specify the return field 
        List<String> list = new ArrayList<>();
        list.add("name");
        list.add("age");
        // Inclusion  Contains the specified fields and ( implicit )_id Field 
        // Exclusion  Contains the specified fields and ( implicit )_id Field 
       Bson fields = Projections.fields(Projections.include(list));
    //4. To query in the specified set 
	MongoCursor<Document> mongoCursor = mongoTemplate.getCollection("weatherall").find(filters).projection(fields).sort(sort).iterator();
            while (mongoCursor.hasNext()) {
    
                Document document = mongoCursor.next();
                //3. Get data according to the field name 
                wdspList.add(document.getDouble("name"));
                wdirList.add(document.getDouble("age"));
                //document.getInteger()
                lstDate.add(DateUtil.format(new Date(document.getLong("date")), "yyyy-MM-dd HH:mm"));
            }