MongoDB Common Commands

Source: Internet
Author: User
Tags mongodb tojson

After the successful start of MongoDB, and then open a command line window input MONGO, you can do some of the database operations.

Enter help to see the basic Operations Command:

Show DBS: Display Database list

Show Collections: Displays a collection in the current database (similar to a table in a relational database)

Show Users: Show user

Use <db name>: Switch the current database, which is the same as the meaning inside the Ms-sql db.help (): Show Database Operations Command, there are many commands db.foo.help (): Display set operation command, also have a lot of commands, Foo refers to the current database, a collection called Foo, not the real Command Db.foo.find (): Data lookup for the Foo collection in the current database (all data is listed due to no conditions) Db.foo.find ({a:1}) : A lookup for the Foo collection in the current database, provided the data has a property called a, and A has a value of 1

MongoDB does not have a command to create a database, but there are similar commands.

For example, if you want to create a "myTest" database, run the use myTest command first, then do something (such as: db.createcollection (' user ')) so that you can create a database called "MyTest".

First, the database commonly used commands

1. Help View command Prompt

Help

Db.help ();

Db.yourColl.help ();

Db.youColl.find (). Help ();

Rs.help ();

2. Switch/CREATE Database

Use Yourdb; The current database is created automatically when a collection (table) is created

3. Query all databases

Show DBS;

4. Delete the currently used database

Db.dropdatabase ();

5. Cloning a database from a specified host

Db.clonedatabase ("127.0.0.1"); Clones data from a database on a specified machine to the current database

6. Copy the specified database data from the specified machine to a database

Db.copydatabase ("MyDB", "temp", "127.0.0.1"), copy the native mydb data to the TEMP database

7. Repairing the current database

Db.repairdatabase ();

8. View the database currently in use

Db.getname ();

db The DB and GetName methods are the same effect and can query the currently used database

9. Display the current DB status

Db.stats ();

10. Current DB version

Db.version ();

11. View the current DB link machine address

Db.getmongo ();

Second, collection aggregation set

1. Create a Clustered collection (table)

Db.createcollection ("Collname", {size:20, Capped:5, max:100});

2. Get a clustered collection with the specified name (table)

Db.getcollection ("account");

3. Get all the aggregation sets of the current DB

Db.getcollectionnames ();

4. Displays the status of all clustered indexes in the current DB

Db.printcollectionstats ();

Third, user-related

1. Add a user

Db.adduser ("name");

Db.adduser ("UserName", "pwd123", true); Add user, set password, read-only

2, database authentication, security mode

Db.auth ("UserName", "123123");

3. Show all current users

Show Users;

4. Delete users

Db.removeuser ("UserName");

Iv. viewing aggregate collection basic information

1, check the help Db.yourColl.help ();

2, query the current collection of data bar number Db.yourColl.count ();

3, view data space size db.userInfo.dataSize ();

4. Get the DB Db.userInfo.getDB () where the current aggregation set resides;

5, get the current gathering state db.userInfo.stats ();

6, get the aggregate aggregate size db.userInfo.totalSize ();

7, aggregate storage space size db.userInfo.storageSize ();

8. Shard Version Information Db.userInfo.getShardVersion ()

9, Aggregation set rename Db.userInfo.renameCollection ("Users"); Rename UserInfo to users

10. Delete the current aggregation set Db.userInfo.drop ();

V. Modify, add, and delete collection data

1, add (save, insert can)

Db.users.save ({name: ' Zhangsan ', age:25, sex:true});

Data column of the added data, not fixed, according to the data added

2. Modification

Db.users.update ({age:25}, {$set: {name: ' ChangeName '}}, False, True);

Equivalent to: Update users set name = ' ChangeName ' where age = 25;

3. Delete

Db.users.remove ({age:132});

4, Query modification Delete

Db.users.findAndModify ({

Query: {age: {$gte: 25}},

Sort: {Age:-1},

Update: {$set: {name: ' A2 '}, $inc: {age:2}},

Remove:true

});

Db.runcommand ({findandmodify: "Users",

Query: {age: {$gte: 25}},

Sort: {Age:-1},

Update: {$set: {name: ' A2 '}, $inc: {age:2}},

Remove:true

});

update or remove One of them is a required parameter; Additional parameters are optional.

Parameters

Detailed

Default value

Query

Query Filter Criteria

{}

Sort

If multiple documents conform to a query filter, the first-ranked object will be selected in the arrangement specified by the parameter, and the object will be manipulated

{}

Remove

If true, the selected object will be deleted before it is returned

N/A

Update

A Modifier object

N/A

New

If true, the modified object is returned instead of the original object. In the delete operation, the parameter is ignored.

False

Fields

See Retrieving a subset of fields (1.5.0+)

All fields

Upsert

Creates a new object if the query result is empty. Example (1.5.4+)

False

VI. Aggregate Collection Query

1. Check all records

Db.userInfo.find ();

Equivalent: select* from UserInfo;

The default is 20 records per page, and you can query the next page of data with the IT iteration command when the display is not displayed. Note: Type the IT command cannot take ";"

However, you can set the size of the data displayed on each page, using dbquery.shellbatchsize= 50, which shows 50 records per page.

2. Duplicate data for a column in the current clustered collection after the query is removed

Db.userInfo.distinct ("name");

Will filter out the same data in name, equivalent to: Select Distict name from UserInfo;

3, conditional query, query age = 22 of the record

Db.userInfo.find ({"Age": 22});

Equivalent to: SELECT * from userInfo where age = 22;

4. Check the records of age > 22

Db.userInfo.find ({age: {$gt: 22}});

Equivalent to: SELECT * from UserInfo where >22;

5. Check the records of age < 22

Db.userInfo.find ({age: {$lt: 22}});

Equivalent to: SELECT * from UserInfo where <22;

6. Check the records of age >= 25

Db.userInfo.find ({age: {$gte: 25}});

Equivalent to: SELECT * from UserInfo where age >= 25;

7. Check the records of age <= 25

Db.userInfo.find ({age: {$lte: 25}});

8. Query age >= 23 and age <= 26

Db.userInfo.find ({age: {$gte: $lte: 26}});

9. Query the data containing MONGO in name

Db.userInfo.find ({name:/mongo/}); Equal to percent

SELECT * from UserInfo where name is like '%mongo% ';

10, query the name in the beginning of MONGO

Db.userInfo.find ({name:/^mongo/});

SELECT * from UserInfo where name is like ' mongo% ';

11. Query the specified column name, age data

Db.userInfo.find ({}, {name:1, age:1});

Equivalent to: Select Name, age from UserInfo;

Of course name can also be used with true or false, as in the case of Ture River Name:1 effect, if False is to exclude name, display column information other than name.

12. Query the specified column name, age data, age > 25

Db.userInfo.find ({age: {$gt: +}}, {name:1, age:1});

Equivalent to: Select Name, age from UserInfo where age >25;

13. Sort by age

Ascending: Db.userInfo.find (). Sort ({age:1});

Descending: Db.userInfo.find (). Sort ({Age:-1});

14. Query name = Zhangsan, age = 22 data

Db.userInfo.find ({name: ' Zhangsan ', age:22});

Equivalent to: SELECT * from userInfo where name = ' Zhangsan ' and "age = ' 22 ';

15, query the first 5 data

Db.userInfo.find (). Limit (5);

Equivalent: selecttop 5 * from UserInfo;

16, query 10 after the data

Db.userInfo.find (). Skip (10);

Equivalent to: SELECT * from UserInfo where ID not in (

Selecttop * from UserInfo

);

17, query the data between 5-10

Db.userInfo.find (). Limit (Ten). Skip (5);

Can be used for pagination, limit is Pagesize,skip is the first few pages *pagesize

18, OR and query

Db.userInfo.find ({$or: [{age:22}, {age:25}]});

Equivalent to: SELECT * from UserInfo where is age = 25

19. Query the first piece of data

Db.userInfo.findOne ();

Equivalent: Selecttop 1 * from UserInfo;

Db.userInfo.find (). limit (1);

20. Query the number of record bars for a result set

Db.userInfo.find ({age: {$gte: +}}). Count ();

Equivalent to: SELECT COUNT (*) from UserInfo where age >= 20;

21. Sort by a column

Db.userInfo.find ({sex: {$exists: true}}). Count ();

Equivalent to: SELECT COUNT (Sex) from userInfo;

Vii. Index

1. Create an index

Db.userInfo.ensureIndex ({name:1});

Db.userInfo.ensureIndex ({name:1, TS:-1});

2. Querying all indexes of the current aggregation collection

Db.userInfo.getIndexes ();

3. View Total index record size

Db.userInfo.totalIndexSize ();

4. Read all index information for the current collection

Db.users.reIndex ();

5. Delete the specified index

Db.users.dropIndex ("Name_1");

6. Delete all index indexes

Db.users.dropIndexes ();

Eight, statement block operation

1. Simple Hello World

Print ("Hello world!");

This notation calls the print function, and writes "Hello world!" directly The effect is the same;

2. Convert an object to JSON

Tojson (New Object ());

Tojson (New Object (' a '));

3. Loop Add data

> for (var i = 0; i < i++) {

... db.users.save ({name: "u_" + I, age:22 + i, sex:i% 2});

... };

This adds 30 data to the loop, and you can also omit the notation

> for (var i = 0; i < i++) Db.users.save ({name: "u_" + I, age:22 + i, sex:i% 2});

is also possible, when you use the Db.users.find () query, display multiple data and can not be displayed on a page, the use of it to view the next page of information;

4. Find Cursor Query

>var cursor = Db.users.find ();

> while (Cursor.hasnext ()) {

Printjson (Cursor.next ());

}

This allows you to query all the users information, as well as to write

var cursor = Db.users.find ();

while (Cursor.hasnext ()) {Printjson (cursor.next);}

You can also omit the {} number

5. Foreach Iteration Loops

Db.users.find (). ForEach (Printjson);

A function must be passed in foreach to process data information for each iteration

6. Treat the Find cursor as an array

var cursor = Db.users.find ();

CURSOR[4];

Get the data for subscript index 4

Since it can be treated as an array, its length can be obtained: Cursor.length (); or cursor.count ();

So we can also display the data in a loop

for (var i = 0, Len = c.length (); i < Len; i++) Printjson (C[i]);

7. Convert the Find cursor to an array

> var arr = db.users.find (). ToArray ();

> Printjson (arr[2]);

To convert it to an array using the ToArray method

8. Customize our own query results

Only age <= 28 is displayed and only the Age column data is displayed

Db.users.find ({age: {$lte: +}}, {age:1}). ForEach (Printjson);

Db.users.find ({age: {$lte: +}}, {age:true}). ForEach (Printjson);

Exclude The Age column

Db.users.find ({age: {$lte: +}}, {Age:false}). ForEach (Printjson);

9. The Foreach transfer function displays information

Db.things.find ({x:4}). ForEach (function (x) {print (Tojson (x));});

Ix. Other

1, the error message before the query Db.getpreverror ();

2, clear Error Record db.reseterror ();

MongoDB Common Commands

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.