MongoDB Basic Usage

MongoDB is an open-source database system based on distributed file storage. The data is stored as a document and data structures are composed of key-value (key=>value) pairs.

A MongoDB document is similar to a JSON object. Field values can contain other documents, arrays, and array of documents.

Start MongoDB Service

CMD into the F:\MongoDB\3.4\bin directory, enter the start command:mongod--dbpath F:\MongoDB\data\db, 27017 words indicating that the service started successfully

Possible errors encountered: shutting down withcode:100

1. Admin start: win+x, then a key, start cmd

2. Set up the MongoDB service as a Windows service:

Mongod--dbpath= "F:\MongoDB\db"--logpath= "F:\MongoDB\Log\mongod.log"--logappend--directoryperdb--servicename " MongoDB "--servicedisplayname" MongoDB "--install

3. Delete Files Mongod.lock and Storage.bson

or Computer Management-services-start

Basic Operation Syntax

1 #Create a database, to display the database, you need to insert at least one file2 Use TestDB3 #Create collection, options (optional) Specify the memory size and index options, in MongoDB, you do not need to create a collection. When inserting some files MongoDB automatically creates the collection4Db.createcollection ("Col", Options)5 #Deleting a database6 db.dropdatabase ()7 #Delete Collection8 Db.collection.drop ()9 Ten #Inserting Data OneDb.testDB.insert ({"name":"Beginner's Tutorial"}) ADb.col.insert ({title:'MongoDB Tutorials',  -Description'MongoDB is a Nosql database', -By'Beginner's Tutorial', theUrl:'http://www.runoob.com', -Tags: ['MongoDB','Database','NoSQL'], -likes:100 - }) + #inserting a document using the Insert () or Save () method to insert a document into the collection -Document= ({title:'MongoDB Tutorials',  +Description'MongoDB is a Nosql database', ABy'Beginner's Tutorial', atUrl:'http://www.runoob.com', -Tags: ['MongoDB','Database','NoSQL'], -likes:100 - }); - Db.col.insert (document) -Db.col.save (document)#If you do not specify the _id field, the Save () method is similar to the Insert () method. If the _id field is specified, the data for the _id is updated.  in  - #Querying documents to Db.mycol.find (). Pretty () + Db.mycol.find ({key1:value1, key2:value2}). Pretty () -Db.mycol.find ({$or: [{key1:value1}, {key2:value2}]}). Pretty () the  *Db.mycol.find ({" by":"Tutorials Yiibai","title":"MongoDB Overview"}). Pretty () $Db.mycol.find ({$or:[{" by":"Yiibai"},{"title":"MongoDB Overview"}]}). Pretty ()Panax NotoginsengDb.mycol.find ("likes": {$gt: 10}, $or: [{" by":"Yiibai"}, {"title":"MongoDB Overview"}]}). Pretty () -  the #update the document by default will only update a single file to update multiple you need to set the parameter ' multi ' to true + db. Collection_name.update (Selectioin_criteria, Updated_data) A  theDb.mycol.update ({'title':'MongoDB Overview'},{$set: {'title':'New MongoDB Tutorial'}}) +Db.mycol.update ({'title':'MongoDB Overview'},{$set: {'title':'New MongoDB Tutorial'}},{multi:true}) -  $ db. Collection_name.save ({_id:objectid (), new_data}) $Db.mycol.save ({"_id": ObjectId (5983548781331ADF45EC7),"title":"Yiibai New Topic"," by":"Yiibai"}) -  - #Delete document, Justone optional set to TRUE or 1, delete only one file the db. Collection_name.remove (Delletion_critteria,justone) - WuyiDb.mycol.remove ({'title':'MongoDB Overview'}) theDb.mycol.remove ({'title':'MongoDB Overview'},1) -  Wu #query projection, when the Find () method is executed, it displays all fields of a document. To limit this, you need to set the field List value 1 or 0. 1 is used to display fields and 0 is used to hide fields -Db. Collection_name.find ({},{key:1}) AboutDb.mycol.find ({},{"title": 1, _id:0}) ${"title":"MongoDB Overview"} -{"title":"NoSQL Overview"} -{"title":"Yiibai Overview"} -  A #sort, 1 for ascending order, and 1 for descending, default ascending +Db. Collection_name.find (). Sort ({key:1}) theDb.mycol.find (). Sort ({"title":-1}) - #Index $Db. Collection_name.ensureindex ({key:1}) theDb.mycol.ensureIndex ({"title": 1})

Reference: Beginner's Tutorial

Mongdb Importing and exporting files

1. Import

Example:mongoimport-d douban-c film--type csv--headerline --file C:\Users\HP\Desktop\codes\DATA\ratings.csv

Grammar Essentials

-D: Database name

-c:collection Name

--type: Imported format default JSON

-F: Imported field names

--headerline: If the imported format is CSV, you can use the header of the first row as the imported field

--file: The file to import

2. Export

Example:mongoexport-d douban-c info-o C:\Users\HP\Desktop\codes\DATA\douban.csv--type csv-f "_id,rate,tag,title"

Syntax Essentials:

-D: Database name

-c:collection Name

-O: The file name of the output

--type: The format of the output, the default is JSON

-F: The Output field, if-type is CSV, you need to add-f "field name"

May encounter error:syntaxerror:missing; Before statement @ (Shell): 1:15

Workaround : Open a cmd write, not in the run MONGO cmd inside, is not a very magical solution

MongoDB Basic Usage