MongoDB Common Operations Command Daquan

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, but 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". There is a table named "User" under the library.

First, the database commonly used commands
1. Help View command Prompt

The code is as follows:

Help
Db.help ();
Db.yourColl.help ();
Db.youColl.find (). Help ();
Rs.help ();

2. Switch/CREATE Database

The code is as follows:

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

3. Query all databases

The code is as follows:

Show DBS;

4. Delete the currently used database

The code is as follows:

Db.dropdatabase ();

5. Cloning a database from a specified host

The code is as follows:

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

The code is as follows:

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

7. Repairing the current database

The code is as follows:

Db.repairdatabase ();

8. View the database currently in use

The code is as follows:

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

The code is as follows:

Db.stats ();

10. Current DB version

The code is as follows:

Db.version ();

11. View the current DB link machine address

The code is as follows:

Db.getmongo ();

Second, collection aggregation set
1. Create a Clustered collection (table)

The code is as follows:

Db.createcollection ("Collname", {size:20, Capped:5, max:100});//Successful creation will show {"OK": 1}
Determine whether the set is a fixed capacity db.collName.isCapped ();

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

The code is as follows:

Db.getcollection ("account");

3. Get all the aggregation sets of the current DB

The code is as follows:

Db.getcollectionnames ();

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

The code is as follows:

Db.printcollectionstats ();

Third, user-related
1. Add a user

The code is as follows:

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

2, database authentication, security mode

The code is as follows:

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

3. Show all current users

The code is as follows:

Show Users;

4. Delete users

The code is as follows:

Db.removeuser ("UserName");

Iv. Aggregation Collection Query
1. Check all records

The code is as follows:

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

The code is as follows:

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

The code is as follows:

Db.userInfo.find ({"Age": 22});
Equivalent to: SELECT * from userInfo where age = 22;

4. Check the records of age > 22

The code is as follows:

Db.userInfo.find ({age: {$gt: 22}});
Equivalent to: SELECT * from UserInfo where >22;

5. Check the records of age < 22

The code is as follows:

Db.userInfo.find ({age: {$lt: 22}});
Equivalent to: SELECT * from UserInfo where <22;

6. Check the records of age >= 25

The code is as follows:

Db.userInfo.find ({age: {$gte: 25}});
Equivalent to: SELECT * from UserInfo where age >= 25;

7. Check the records of age <= 25

The code is as follows:

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

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

The code is as follows:

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

9. Query the data containing MONGO in name

The code is as follows:

Db.userInfo.find ({name:/mongo/});
Equal to percent
[Code]select * from UserInfo where name like '%mongo% ';

10, query the name in the beginning of MONGO

The code is as follows:

Db.userInfo.find ({name:/^mongo/});
SELECT * from UserInfo where name is like ' mongo% ';

11. Query the specified column name, age data

The code is as follows:

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

The code is as follows:

Db.userInfo.find ({age: {$gt: +}}, {name:1, age:1});
Equivalent to: Select Name, age from UserInfo where age >25;

13. Sort by age

The code is as follows:

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

14. Query name = Zhangsan, age = 22 data

The code is as follows:

Db.userInfo.find ({name: ' Zhangsan ', age:22});
Equivalent to: SELECT * from userInfo where name = ' Zhangsan ' and "age = ' 22 ';

15, query the first 5 data

The code is as follows:

Db.userInfo.find (). Limit (5);
Equivalent: selecttop 5 * from UserInfo;

16, query 10 after the data

The code is as follows:

Db.userInfo.find (). Skip (10);
Equivalent to: SELECT * from UserInfo where ID not in (
Selecttop * from UserInfo
);

17, query the data between 5-10

The code is as follows:

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

The code is as follows:

Db.userInfo.find ({$or: [{age:22}, {age:25}]});
Equivalent to: SELECT * from UserInfo where is age = 25

19. Query the first piece of data

The code is as follows:

Db.userInfo.findOne ();
Equivalent: Selecttop 1 * from UserInfo;
Db.userInfo.find (). limit (1);

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

The code is as follows:

Db.userInfo.find ({age: {$gte: +}}). Count ();
Equivalent to: SELECT COUNT (*) from UserInfo where age >= 20;

21. Sort by a column

The code is as follows:

Db.userInfo.find ({sex: {$exists: true}}). Count ();
Equivalent to: SELECT COUNT (Sex) from userInfo;

Five, index
1. Create an index

The code is as follows:

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

2. Querying all indexes of the current aggregation collection

The code is as follows:

Db.userInfo.getIndexes ();

3. View Total index record size

The code is as follows:

Db.userInfo.totalIndexSize ();

4. Read all index information for the current collection

The code is as follows:

Db.users.reIndex ();

5. Delete the specified index

The code is as follows:

Db.users.dropIndex ("Name_1");

6. Delete all index indexes

The code is as follows:

Db.users.dropIndexes ();

Vi. Modify, add, and delete collection data
1. Add

The code is as follows:

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

Data column of the added data, not fixed, according to the data added
2. Modification

The code is as follows:

Db.users.update ({age:25}, {$set: {name: ' ChangeName '}}, False, True);
Equivalent to: Update users set name = ' ChangeName ' where age = 25;
Db.users.update ({name: ' Lisi '}, {$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

The code is as follows:

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

4, Query modification Delete

The code is as follows:

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.
Parameter details default value
Query filter Condition {}
Sort if multiple documents conform to the query filter criteria, the object that is ranked first is selected in the arrangement specified by the parameter, and the object is manipulated {}
Remove if True, the selected object will be deleted before returning N/a
Update a Modifier object
N/A
If new is 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 Create a new object if the query result is empty. Example (1.5.4+)
False
Seven, statement block operation
1. Simple Hello World

The code is as follows:

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

The code is as follows:

Tojson (New Object ());
Tojson (New Object (' a '));

3. Loop Add data

The code is as follows:

> 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

The code is as follows:

> 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

The code is as follows:

>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

The code is as follows:

var cursor = Db.users.find ();
while (Cursor.hasnext ()) {Printjson (cursor.next);}

You can also omit the {} number
5. Foreach Iteration Loops

The code is as follows:

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

The code is as follows:

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

The code is as follows:

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

7. Convert the Find cursor to an array

The code is as follows:

> 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

The code is as follows:

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

Exclude The Age column

The code is as follows:

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

9. The Foreach transfer function displays information

The code is as follows:

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

Viii. Other
1, the error message before the query

The code is as follows:

Db.getpreverror ();

2. Clear the Error Record

The code is as follows:

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 ();

The code is as follows:

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 Common Operations Command Daquan