MongoDB Note 1 (Basic operations, additions and deletions)

1. Querying an existing database
   

>show DBS

2. Create a database, you need to create a collection this Coucay creates

>use MyDB

3. View Collections

>show Collections or >show tables

4. Create a document and insert data

>db.userinfo.insert ({_id:1,name: "Xiaoming"})

5. Bulk Insert document, Shell is not support bulk INSERT, want to complete bulk insert can be used in MongoDB application driver or shell for loop

>for (var i =0;i<10;i++) {.. Db.userInfo.insert ({name:i}):}

6. View the contents of the document

>db.userinfo.find ()

7.save operation, the save operation and the insert operation differ in the case of encountering _id in the same situation

Save operation completed

Insert will error

> Db.userInfo.insert ({_id:1,name: "Xiaoming"}) Writeresult ({"ninserted": 1}) > Db.userInfo.insert ({_id:1,name: "Xiaocang"}) Writeresult ({"ninserted": 0, "Writeerror": {"code": 11000, "errmsg": "Insertdocument:: Caused by:: 11000 E 11000 duplicate key error index:foobar.userinfo.$_id_ dup key: {: 1.0} "}}" > Db.userInfo.save ({_id:1,name: "Xiaocang" }) Writeresult ({"nmatched": 1, "nupserted": 0, "nmodified": 1})

8. Delete all the data in the list, the collection and index will not be deleted

> Db.userInfo.remove ({}) Writeresult ({"nremoved": 1}) > Db.userInfo.find () > Show Collectionssystem.indexesuserinfo

9. Delete by condition

Db. [Documentname].remove ({})

Delete a record in the collection with name equal to Xiaoming

Db.userInfo.remove ({name: "Xiaoming"})

This article is from a "little progress every Day" blog, make sure to keep this source http://08jw3.blog.51cto.com/998816/1675975

MongoDB Note 1 (Basic operations, additions and deletions)