MongoDB basic operation instructions

Database operations

• Boot mongod --dbpathpath data stored (data used to store a file folder)
• Use the database mongo(reopen a terminal)
• Import Data mongoimport
• List all databases show dbs
• Use / Create Database use xxx
• View the current database db
• Display the collection in the current database show collections

Data addition, deletion and modification

1. Insert data

• Insert a piece of data (as the specific data is inserted, the database is successfully created)
  db.tmp.insert({"name": "xxx"})
• It is impossible to manually insert each piece of data, so you can write the database in the external form and import it into the specific database the database
  mongoimport --db item--collection tmp--drop --file D:\Users\xxx\xxx\xxx.json
　--db item　　to be imported into the data
  　--collection tmp　　the specific collection of the database to import the gold
  　--drop　　data Clear the
  　--file xxx.json　　data in the item Externally write the data file

2. Delete data

• Delete database (delete the current database)
  db.dropDatabase()
• Delete collection
  db.tmp.drop()
• Delete the document (delete all data, but the collection itself is still null)
  db.tmp.remove()
• Delete document (delete all data whose name is Json)
  db.tmp.remove({"name":"xxx"})
• Delete the document (delete the first data whose name is Json)
  db.tmp.remove({"name":"xxx"},{justOne:true})

3. Modify the data

• Change the age of the first data with id 9999 to 100
  db.tmp.update({"id":"9999"},{$set:{"age":10}})
• Change the age of all sex data to 100
  db.tmp.update({"sex": "男"}, {$set: {"age": 10}}, {multi:true})
• Complete replacement / rewriting (the $ set keyword does not appear)
  db.tmp.update({"id": "9999"}, {"name": "ccc", "age":10})
• Method for adding data to data of one record in database
  db.tmp.update({"id": "9999"}, {$addToSet:{comment: {"name" : "xxx", "sex" : "xxx", "age" : "xxx"}}})

4. Query data

• Find the database (already entered a specific database)
  use item　into the database
  show collections　list collection
• Find all the data in the database
  db.tmp.find()
db.getCollection('add').find()
• Exact match　
  db.tmp.find({"name":"xxx"})
• Multiple conditions　
  db.tmp.find({"name":"xxx","age":10})
• Greater than condition　
  db.tmp.find({"age":{$gt:20}})
• or　　　
  db.tmp.find({$or:[{"age":10},{"age": 100}]})
• Sort　　　
  db.tmp.find().sort({"age": 1})