MongoDB Basic command with

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 in Ms-sql
Db.help (): Show database Operations Command with a lot of commands
Db.foo.help (): Displays the set Operation command, as well as a lot of commands, Foo refers to the current database, a collection called Foo, not the real meaning of the command
Db.foo.find (): Data lookup for the Foo collection in the current database (all data is listed because there are no conditions)
Db.foo.find ({a:1}): Looks 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".

Database Common 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();

Collection Aggregation Collection

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();

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");

other1, the error message before the query db. Getpreverror(); 2, clear Error Record db. Reseterror();View 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 ();

Clustered collection Query

1. Check all records

DB. userInfo. Find();

Equivalent to: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 ";"

But you can set the size of the data displayed per page, using Dbquery. shellbatchsize=; This results in 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 : Select Distict name from UserInfo;

3. Check the record of age = 22

DB. userInfo. Find({"Age": 22});

Select = $;

Records for > 22

DB. userInfo. Find({age: {$gt: 22}});

Equivalent:select>;

Records for < 22

DB. userInfo. Find({age: {$lt: 22}});

Equivalent:select<;

>= 25 of records

DB. userInfo. Find({age: {$gte: 25}});

Equivalent:select>=;

<= 25 of records

DB. userInfo. Find({age: {$lte: 25}});

> <= 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.

> 25

DB. userInfo. Find({age: {$gt: +}}, {name:1, age:1});

Equivalent:select>;

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* from UserInfo;

16, query 10 after the data

DB. userInfo. Find(). Skip(10);

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

Select Top Ten * from UserInfo

);

17, query the data between 5-10

DB. userInfoFind()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:select=;

19. Query the first piece of data

DB. UserInfo. FindOne();

Equivalent:selecttop* 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:select>=;

21. Sort by a column

DB. userInfo. Find({sex: {$exists: true}}). Count();

Equivalent to:select count (Sex) from UserInfo;

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();

Modify, add, and delete collection data

1. Add

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

= 25;

DB. Users. Update({name: ' Lisi '}, {$inc: {age:50}}, False, True);

Equivalent to: Update users set age = Age + where name = ' Lisi ';

DB. Users. Update({name: ' Lisi '}, {$inc: {age:50}, $set: {name: ' HoHo '}}, False, True);

Equivalent to: Update users set age = Age +, name = ' HoHo ' WHERE name = ' Lisi ';

3. Delete

DB. Users. Remove({age:132});

4, Query modification Delete

DB. Users. Findandmodify({

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

    Remove:true

});

DB. RunCommand

    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

Statement block operations

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 (vari= 0; I < ; I+ +) {

.. db. Users. Saveiii % 2});

... };

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

> for (vari= 0; I < ; I+ +) db. Users. Saveiii % 2});

It is also possible to use it to view the information on the next page when you use the DB. Usersfind() query to display multiple data without a single page display.

4. Find Cursor Query

> var cursor = DB. Users. Find();

> while (cursor. Hasnext

    Printjson (cursornext

}

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. Usersfind(). 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, you can get its length:cursor. Length(), or cursor. Count();

So we can also display the data in a loop

for (vari = 0, Len = C. lengthi<Len; I+ +) Printjson (c[i]);

7. Convert the Find cursor to an array

> var arr = db. Usersfind(). ToArray();

> Printjson (arr[2]);

To convert it to an array using the ToArray method

8. Customize our own query results

<= 28 and displays only the age column data

DB. UsersFind({age: {$lte: Age:1}). ForEach(Printjson);

DB. UsersFind({age: {$lte: Age:true}). ForEach(Printjson);

Exclude The Age column

DB. UsersFind({age: {$lte: Age:false}). ForEach(Printjson);

9. The Foreach transfer function displays information

DB. Things. Find({x:4}). ForEach(function (x) {print (Tojson (x));});

MongoDB Basic command with