MongoDB basic operations in Python: Connecting, querying instances _python

MongoDB is a database based on distributed file storage. Written by the C + + language. A high-performance data storage solution designed to provide an exhibition for Web applications. It is characterized by high-performance, easy to deploy, easy to use, storage data is very convenient.

MongoDB Simple to use

Join database

Copy Code code as follows:

In [1]: Import Pymongo
In [2]: from Pymongo import Connection
In [3]: Connection = connection (' 192.168.1.3 ', 27017)//Create Join

Connection Related parameters

Copy Code code as follows:

Connection ([host= ' localhost ' [, port=27017[, pool_size=none[, auto_start_request=none[, timeout=none[, slave_okay= false[, network_timeout=none[, document_class=dict[, Tz_aware=true]]]]

Database operations

Copy Code code as follows:

In [9]: C.database_names ()//list all database names
OUT[9]: [u ' Test ', u ' admin ', U ' yuhen ', U ' SMS ', U ' Local ']

In [ten]: C.server_info ()//view server-related information
OUT[10]:
{u ' bits ': 64,
U ' gitversion ': U ' nogitversion ',
U ' OK ': 1.0,
U ' sysinfo ': U ' Linux yellow 2.6.24-27-server #1 SMP Fri Mar 01:23:09 UTC x86_64 '
U ' version ': U ' 1.2.2 '}

in [[]: db = c[' Test ']//Select database
in [[]: Db.collection_names ()//list all collection names in the current database
OUT[17]: [u ' system.indexes ', U ' fs.files ', U ' fs.chunks ', U ' Test_gao ']

in [[]: db.connection//view join information
OUT[23]: Connection (' 192.168.1.3 ', 27017)

in [[]: Db.create_collection (' test_abeen ')//Create a new collection
OUT[24]: Collection (Database (Connection (' 192.168.1.3 ', 27017), U ' Test '), U ' Test_abeen ')

in [/]: Db.last_status ()//view last operation status
OUT[25]: {u ' err ': None, U ' n ': 0, U ' OK ': 1.0}

in [[]: Db.name//view Current database name
OUT[26]: U ' test '

In [$]: Db.profiling_info ()//view configuration information
OUT[27]: []

in [[]: Db.profiling_level ()
OUT[28]: 0.0

Collection operations

Copy Code code as follows:

In [to]: Db.collection_names ()//View all collection names for the current database
OUT[31]:
[u ' system.indexes ',
U ' fs.files ',
U ' fs.chunks ',
U ' Test_gao ',
U ' system.users ',
U ' Test_abeen ']

In [£]: c = db.test_abeen//Select Collection
In [per]: c.name//view current collection name
OUT[33]: U ' test_abeen '

in [[]: C.full_name//View the full name of the current collection
OUT[35]: U ' test.test_abeen '
in [+]: c.database//view current collection database related information
OUT[36]: Database (Connection (' 192.168.1.3 ', 27017), U ' Test ')

in [[): Post = {"Author": "Mike", "text": "This is a test by Abeen"}
in [[]: Posts = db.posts
in [[]: Posts.insert (POST)//Insert document to database collection, default to create collection
OUT[40]: ObjectId (' 4c358492421aa91e70000000 ')
in [[]: Db.collection_names ()//Display all collection names
OUT[41]:
[u ' system.indexes ',
U ' fs.files ',
U ' fs.chunks ',
U ' Test_gao ',
U ' system.users ',
U ' Test_abeen ',
U ' posts ']

in [[]: Posts.find_one ()/Find information from the collection
Out[42]:
{u ' _id ': ObjectId (' 4c358492421aa91e70000000 '),
  U ' author ': U ' Mike ',
 u ' text ': U ' this are a test by Abeen '}
in [?]: P.update ({"Author": "Mike"},{"$set": {"auth or ': ' Abeen ', ' text ': ' This is a test by Abeen Shan Shan '}}//Update collection Document Information
in [?]: List (P.find ())
Out[55]:
[{u ' _id ': ObjectId (' 4c358492421aa91e70000000 '),
  U ' author ': U ' abeen ',
  u ' text ': U ' is a test by Abeen Shan Shan '}]

In [%]: List (Posts.find ())
out[96]:
[{u ' _id ': ObjectId (' 4c358492421aa91e70000000 '),
  U ' author ': U ' Mike ',
  u ' text ': U ' is a test by Abeen '},
 {u ' _id ': ObjectId (' 4c358ad4421aa91e70000002 '), U ' A ': u ' AA ', U ' b ': U ' BB '},
 {u ' _id ': ObjectId (' 4c358ad9421aa91e70000003 '), U ' a ': U ' AA ', U ' b ': U ' BB '},
 {u ' _ Id ': ObjectId (' 4c358abb421aa91e70000001 '),
  U ' a ': U ' abeen ',
  u ' B ': U ' this bb are updated '}]
in [97] : Posts.remove ({"A": "Abeen"})//delete eligible documents
in [?]: List (Posts.find ())
Out[98]:
[{u ' _id ': ObjectId (' 4c358492421aa91e70000000 '),
  U ' author ': U ' Mike ',
  u ' text ': U ' is a test by Abeen '},
 {u ' _ Id ': ObjectId (' 4c358ad4421aa91e70000002 '), U ' a ': U ' AA ', U ' b ': U ' BB '},
 {u ' _id ': ObjectId (' 4c358ad9421aa91e70000003 '), U ' a ': U ' AA ', U ' b ': U ' BB '}]

In [102]: Db.collection_names ()
OUT[102]:
[u ' system.indexes ',
U ' fs.files ',
U ' fs.chunks ',
U ' Test_gao ',
U ' system.users ',
U ' Test_abeen ',
U ' posts ',
U ' Doc_abeen ']

in [[]: Db.drop_collection ("Doc_abeen")//Delete collection
In [the]: Db.collection_names ()
OUT[105]:
[u ' system.indexes ',
U ' fs.files ',
U ' fs.chunks ',
U ' Test_gao ',
U ' system.users ',
U ' Test_abeen ',
U ' posts ']

Code

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In [113]: result = Db.posts.find ({"A": "AA"})/Lookup
In [114]: type (Result)
OUT[114]: <class ' pymongo.cursor.Cursor ' >
In [119]: List (result)
OUT[119]:
[{u ' _id ': ObjectId (' 4c358ad4421aa91e70000002 '), U ' a ': U ' AA ', U ' b ': U ' BB '},
{u ' _id ': ObjectId (' 4c358ad9421aa91e70000003 '), U ' a ': U ' AA ', U ' b ': U ' BB '}]

Find format

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Find ([spec=none[, fields=none[, skip=0[, limit=0[, timeout=true[, snapshot=false[, tailable=false[, sort=None[, Max_ scan=none[, as_class=none[, **kwargs]] []]]

Code

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In [£]: Db.posts.count ()//Current collection document Count
OUT[120]: 3
In [121]: type (db.posts)
OUT[121]: <class ' pymongo.collection.Collection ' >

In [138]: Posts.rename (' test_abeen ')//renaming the current collection
In [139]: Db.collection_names ()
OUT[139]:
[u ' system.indexes ',
U ' fs.files ',
U ' fs.chunks ',
U ' Test_gao ',
U ' system.users ',
U ' Test_abeen ']

In [151]: for post in C.find ({"A": "AA"}). Sort ("a")://Query side-by-side sequence
Post
OUT[152]: {u ' _id ': ObjectId (' 4c358ad4421aa91e70000002 '), U ' a ': U ' AA ', U ' b ': U ' BB '}
OUT[152]: {u ' _id ': ObjectId (' 4c358ad9421aa91e70000003 '), U ' a ': U ' AA ', U ' b ': U ' BB '}

Copy Code code as follows:

> Db.foo.insert ({x:1, y:1})
> Db.foo.insert ({x:2, y: "string"})
> Db.foo.insert ({x:3, y:null})
> Db.foo.insert ({x:4})

Query #1 y is null or does not exist
> Db.foo.find ({"Y": null})
{"_id": ObjectId ("4dc1975312c677fc83b5629f"), "X": 3, "Y": null}
{"_id": ObjectId ("4dc1975a12c677fc83b562a0"), "X": 4}

Query #2 y-null value
> Db.foo.find ({"Y": {$type: 10}})
{"_id": ObjectId ("4dc1975312c677fc83b5629f"), "X": 3, "Y": null}

Query #3 y results that do not exist
> Db.foo.find ({"Y": {$exists: false}})
{"_id": ObjectId ("4dc1975a12c677fc83b562a0"), "X": 4}