Mongodb exploration phase [easy to understand]

Hello everyone , I meet you again , I'm the king of the whole stack .

1. database

One mongodb Multiple databases can be set up in .

MongoDB The default database is ”db”, The database is stored in data Directory .

MongoDB Can hold multiple independent databases , Each has its own set and permissions , Different databases are also placed in different files .

“show dbs” The command displays a list of all the data . Equate to MySQL show databases;

If you want to view all databases , have access to show dbs command ：

db: Default database name ; test: Table name insert: The insert find： Query operation

perform “db” The command can display the current database object or collection .

2.linux platform mongodb Background daemons start

Mongodb You can use the command line and How to profile To start up , The specific command is as follows ：

Command line ：

[[email protected] mongodb]# ./bin/mongod --dbpath=/data/db 

Copy

The configuration file ：

[[email protected] mongodb]# ./bin/mongod -f mongodb.conf  

Copy

But these two methods are launched in the foreground Mongodb process , If Session The window closed ,Mongodb And then the process stops . however Mongodb It also provides a backstage Daemon Mode start , Just add one ”–fork” Parameters can be , It is worth noting that , Yes ”–fork” Parameters must be enabled ”–logpath” Parameters .

As shown below ：

[[email protected] mongodb]# ./bin/mongod --dbpath=data/db --fork  
--fork has to be used with --logpath  
[[email protected] mongodb]# ./bin/mongod --dbpath=data/db --fork --logpath=log/mongodb.log   
all output going to: /opt/mongodb/log/mongodb.log  
forked process: 3300  
[[email protected] mongodb]#   

Copy

daemon Way to start fork Parameters can also be configured in the configuration file , As shown below ：

port=27017  
dbpath=data/db  
logpath=log/mongodb.log  
logappend=true  
fork=true  

Copy

Then start through the configuration file mongodb Also started in the background ：

[[email protected] mongodb]# ./bin/mongod -f mongodb.conf   
all output going to: /opt/mongodb/log/mongodb.log  
forked process: 3377  

Copy

3.MongoDB The database is in the form of service Windows In the background

mongod --dbpath d:\mongodb\data\db --logpath d:\mongodb\log\MongoDB.log --install --serviceName "MongoDB" 

Copy

Add directly to the system service , After execution, I will start , Start up is also self starting

Reference resources ：windows Next MongoDB Installation , Configuration and startup – Urban fireworks – Blog Garden

4.mongo.cfg file

systemLog:
    destination: file
    path:  D:\softwore\mongodb3\data\log\mongod.log
storage:
    dbPath: D:\softwore\mongodb3\data\db

Copy

5.MongoBooster The graphical interface

NoSQLBooster – The Smartest GUI Tool and IDE for MongoDB

6. use show dbs see , Always only local A database ？

use newdbname ; Switch or create a new set （ Creation time , Only after inserting data , The new set is effective ）

Use command “use Database name ”, Just mark that you want to create a new database , But there is actually no data written , therefore mongodb You won't really create a database ; You have to write data under the new database , for example :

db.test.insert({"key":"value"})

Copy

7.MongoDB Common sentences

use DATABASE_NAME    If the database doesn't exist , Then create the database , Otherwise switch to the specified database .
show dbs              View all databases 
db.dropDatabase()     Delete the current database , The default is  test, You can use  db  Command to view the current database name 
db.createCollection(name, options)   Create set , Similar to tables in a database ,
db.collectionName.drop()      Delete the collection 
show tables             #  Alias , show collections   The command will be more accurate 
db.COLLECTION_NAME.insert(document)   Inserted into the document 
db.COLLECTION_NAME.save(document)   Inserted into the document , The method is obsolete in the new version ,db.collection.insertOne()  or  db.collection.replaceOne()  Instead of 
db.collection.insertOne()        Insert a document ,3.2  After the new version  
db.collection.insertMany()       Insert multiple documents ,3.2  After the new version  
update()  and  save() Method to update the document in the collection 
db.collection.remove(<query>, <justOne>)         MongoDB  Delete the document 
db.col.remove({})              Delete all data , Similar to the conventional  SQL  Of  truncate  command 
db.col.find().pretty()        Query the document , Read data in an easy to read way 
db.col.find({likes : {$gt : 100}})     Greater than operator  - $gt
db.COLLECTION_NAME.find().limit(NUMBER).skip(NUMBER)  limit Method ,skip Method 
db.COLLECTION_NAME.find().sort({KEY:1})  
db.collection.createIndex(keys, options)  Create index 
db.COLLECTION_NAME.aggregate(AGGREGATE_OPERATION)   polymerization (aggregate) It's mainly used to process data ( Such as the statistical average , Make a peace, etc ), And return the calculated data result 
mongostat  and  mongotop     monitor MongoDB Operating condition 
mongodump                  Backup 
mongorestore               recovery 
explain()  and  hint()         Common functions for query analysis 
db.runtest.find({post_text:/runoob/i})   Regular   matching post_text Contained in the runoob  Documents ,i  Case insensitive 

Copy

use  Database name   Access to database   If the database does not exist , Create database 

db  Show current database 

show dbs  Display the database with non empty content 

db.createCollection(' Table name ')  Create an unlimited length table 

db.createCollection(' Table name ' ,{capped：true,size：1000}）  Create a table with limited length 

db. Table name .drop()  Delete the collection 

show collections  Show all tables 

db. Table name .find()  Look up table data 

db. Table name .find({ Name : data 1})  Query by criteria 

db. Table name .find({ Name : data 1}).pretty() pretty()  Format the result of tape search , It is easier to see the structure and content 

db. Table name .findOne({ Name : data 1})  Query by criteria , Only return to the first 

db. Table name .update({ Name : data 1},{ Name ： data 2})  Find data 1 , Replace with data 2

db. Table name .update({ Name : data 1},{$set:{ Name ： data 2}})  Find the column as data 1 Of , Replace all data 1 For data 2

db. Table name .remove({ Name : data 1},{justOne:true})  Delete data 1 The line of ,justOne by true Delete 1 strip , by false Delete multiple items when 

 Comparison operator  ：

 Less than  $lt  Less than or equal to  lte Greater than gt  Greater than or equal to gte It's not equal to ne

 Logical operators ：

or Or, and you can connect with commas directly in  stay ... in 

 Sort ： sort（）

db. Table name .find().sort({ Field ： Parameters })  Parameter is 1  Ascending   Parameter is -1  Descending 

 Pagination  ：limit（）

db. Table name .find().limit( Parameters )  The parameter is the number of entries obtained 

db. Table name .find().skip( Parameters )  The parameter is the number of skips 

db. Table name .count（{ Name : data 1}） Number of Statistics 

db. Table name .find( Name : data 1).distinct(' De duplicate fields ',{ Name : data 2})  Remove duplicates 

 Backup database 

mongodump -h ip Address  -d  Database name  -o Storage location 

 Recover database 

mongorestore -h ip Address  -d  Database name  -dir Storage location 

Copy

8.MongoDB polymerization

>db.lxwdb.aggregate([{$group:{_id:"$title",num_count:{$sum:1}}}])
{ "_id" : "mongodb_test", "num_count" : 4 }
{ "_id" : "mongodb_test123", "num_count" : 1 }
{ "_id" : "update_mongodb", "num_count" : 1 }
{ "_id" : "MongoDB  course ", "num_count" : 2 }
{ "_id" : null, "num_count" : 1 }
> db.lxwdb.find()
{ "_id" : ObjectId("613ef95fd1067f6f0d0d1aaa"), "name" : "newlxw" }
{ "_id" : ObjectId("613f0a50d1067f6f0d0d1aad"), "title" : "MongoDB  course ", "description" : "MongoDB  It's a  Nosql  database ", "by" : " Novice tutorial ", "url" : "http://www.runoob.com", "tags" : [ "
mongodb", "database", "NoSQL" ], "likes" : 100 }
{ "_id" : ObjectId("613f0a56d1067f6f0d0d1aae"), "title" : "MongoDB  course ", "description" : "MongoDB  It's a  Nosql  database ", "by" : " Novice tutorial ", "url" : "http://www.runoob.com", "tags" : [ "
mongodb", "database", "NoSQL" ], "likes" : 100 }
{ "_id" : ObjectId("613f0bb70c79827ceaac2d23"), "title" : "update_mongodb" }
{ "_id" : ObjectId("613f0f970c79827ceaac2d27"), "title" : "mongodb_test123" }
{ "_id" : ObjectId("613f0f960c79827ceaac2d26"), "title" : "mongodb_test", "age" : 4 }
{ "_id" : ObjectId("613f16540c79827ceaac2d28"), "title" : "mongodb_test", "age" : 4 }
{ "_id" : ObjectId("613f16ba0c79827ceaac2d29"), "title" : "mongodb_test", "age" : 4 }
{ "_id" : ObjectId("613f16dc0c79827ceaac2d2a"), "title" : "mongodb_test", "age" : 5 }

Copy

 db.lxwdb.aggregate([{$group:{_id:"$title",num_count:{$sum:1}}}])

Copy

$group: Grouping statistics

_id: As id Field of , Unable to change

num_count: Count the number of this group , Self defined , Can be changed

Through fields title Fields group data , And calculate title The sum of the same values of the fields .

 Equate to ： select title, count(*) from lxwdb group by title

Copy

9. problem ：Win PHP5.6 Wrong presentation Fatal error: Class ‘MongoClient’ not found

Information searched on the Internet , After looking carefully, I found that the two extension names are different . PHP5.6 need php_mongo.dll instead of php_mongodb.dll. download php_mongo.dll Can be installed .

10.PHP call

header("Content-Type: text/html; charset=utf-8");
$m = new MongoClient(); //  The default connection host and port is ：mongodb://localhost:27017
$db = $m->lxwdb; //  Select database 
//$db->createCollection('runtest'); // Create set 
$collection=$db->runtest; // Select collection 
$document=array(
	"title" => "MongoDB",
	"description" => "database",
	"likes" => 100,
	"url" => "http://www.runoob.com/mongodb/",
	"by", " Novice tutorial "
);
// Inserted into the document 
$res=$collection->insert($document);
echo ' Data insertion successful ';

// Query the document 
$result=$collection->find();
foreach ($result as $res){
	d($res['title']);
}

// Update the document 
$collection->update(array("title"=>"MongoDB-11"),array('$set'=>array("title"=>"MongoDB-112")),array('multiple'=>true));
$result=$collection->findOne();
foreach ($result as $res){
	d($res);
}

// Delete the document 
$res=$collection->remove(array('0'=>false),array('justOne'=>false));
$res=$collection->remove(array('title'=>'MongoDB  course '),array('justOne'=>true));

function d($data, $label='')
{
	$ajax = isset($_SERVER['HTTP_X_REQUESTED_WITH']) && ($_SERVER['HTTP_X_REQUESTED_WITH'] == 'XMLHttpRequest');

	if(!$ajax) echo '<pre style="text-align: left;">';
	if($label) echo $label.'--------------------------<br/>';
	print_r($data);
	if(!$ajax) echo '</pre>';
}

Copy

Publisher ： Full stack programmer stack length , Reprint please indicate the source ：https://javaforall.cn/111436.html Link to the original text ：https://javaforall.cn