Mongo DB intro
http://docs.mongodb.org/manual/tutorial/getting-started-with-the-mongo-shell/ Getting Started with the mongo Shell
http://docs.mongodb.org/manual/reference/glossary/ Glossary
0.
mongod.exe : the server
mongo.exe: the shell
collection ---- a table in relational DB
A grouping of MongoDB documents. A collection is the equivalent of an RDBMS table.
document ---- a entry in relational table
A record in a MongoDB collection and the basic unit of data in MongoDB.
1. show all db/ collections
show dbs
show collections
http://docs.mongodb.org/manual/reference/mongo-shell/
2. display current database that you're using
db
3. switch database
use <database name>
4. insert
db.<collection name>.insert(<json data>) db.users.insert({'name':'steve','age':'1'})
python
richard ={"name":"Richard Kreuter"}
people.insert(richard)
5. save
db.users.save({'name':'steve','age':'1'})
http://stackoverflow.com/questions/16209681/what-is-the-difference-between-save-and-insert-in-mongo-db
6. find （输出）
db.<collection name>.find() db.users.find()
db.users.find({a:1})
find with format
db.users.find().pretty()
specifying field
db.u.findOne({"name":"haha"},{"name":true})
// return name and _id
db.u.findOne({"name":"haha"},{"name":true,"_id":false})
// only return name
db.u.findOne({"name":"haha"},{"name":1,"_id":0})
// true =1, false =0
7. update a document
http://docs.mongodb.org/manual/reference/operator/update-field/
7.1 rewplace a document
db.u.update({"_id":"123"},{"popu":100})
python
score = scores.find_one({'student_id':1, 'type':'homework'})
score['review_date'] = datetime.datetime.utcnow()
scores.update({'student_id':1, 'type':'homework'}, score)
7.2 using $set
db.users.update({"_id":"apple"},{$set:{"country":"RU"}})
python
scores.update({'student_id':1, 'type':'homework'},
{'$set':{'review_date':datetime.datetime.utcnow()}})
7.3 find object, change and save
> db.users.find().pretty() { "_id" : ObjectId("53e2b118441a819bd2b7cad5"), "name" : "nkdsnckdsn", "age" : "1" } { "_id" : ObjectId("53e2bba8441a819bd2b7cada"), "name" : "apple", "age" : "2" } { "_id" : ObjectId("53e2bbb2441a819bd2b7cadb"), "name" : "banana", "age" : "3" }
> var h = db.users.findOne({"name":"apple"})
> h
{
"_id" : ObjectId("53e2bba8441a819bd2b7cada"),
"name" : "apple",
"age" : "2"
}
> h.age = '3'
3
> db.users.save(h)
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
python
score = scores.find_one({'student_id':1, 'type':'homework'})
score['review_date'] = datetime.datetime.utcnow()
scores.save(score)
8. import
import db
mongorestore [db foldername]
import json file into db
mongoimport -d students -c grades < grades.json
http://docs.mongodb.org/manual/reference/program/mongoimport/
9. greater, less, greater or equal, less or equal
http://docs.mongodb.org/manual/reference/operator/query/
Query and Projection Operators
db.u.find({"student":{$gt:50}})
10. $exists, $regex, $type
| Type | Number |
| Double | 1 |
| String | 2 |
| Object | 3 |
| Array | 4 |
| Binary data | 5 |
| Undefined | 6 |
| Object id | 7 |
http://docs.mongodb.org/manual/reference/bson-types/ BSON Types
find all documents whose name type is double
db.u.find({name:{$type:1}})
where the name has a "q" in it, and the document has an email field.
db.users.find({ name : { $regex : "q" }, email : { $exists: true } } );
11. $or
find all documents in the scores collection where the score is less than 50 or greater than 90
db.scores.find({$or:[{score:{$lt:50}},{score:{$gt:90}}]})
12. dot
{ product : "Super Duper-o-phonic",
price : 100000000000,
reviews : [ { user : "fred", comment : "Great!" , rating : 5 },
{ user : "tom" , comment : "I agree with Fred, somewhat!" , rating : 4 } ],
... }
Write a query that finds all products that cost more than 10,000 and that have a rating of 5 or better.
db.catalog.find({price:{$gt:10000},"reviews.rating":{$gte:5}})
13. sort(), skip(), limit()
always in this order : sort, skip, limit
db.u.find().sort({student:-1})
db.u.find().limit(10)
db.u.find().skip(20)
python
collection.find().sort('field', pymongo.ASCENDING):
14. cursor
cur=db.u.find();null;
cur.hasNext()
while(cur.hasNext()) printjson(cur.next())
15. upsert (if document exist then insert, otherwise create new one)
db.foo.update( { username : 'bar' }, { '$set' : { 'interests': [ 'cat' , 'dog' ] } } , { upsert : true } );
python
stuff.update({'_id':'bat'}, {'friend':'ball', 'cousin':'glove'}, upsert=True)
stuff.update({'_id':'bat'}, {'_id':'bat', 'friend':'ball', 'cousin':'glove'}, upsert=True)
stuff.update({'_id':'bat'}, {'$set': {'friend':'ball', 'cousin':'glove'}}, upsert=True)
16. load js
mongo --shell [db name] homework2.js
17. dump
mongorestore folder_name
18. drop(delete) database
db.dropDatabase()