MongoDB command use Daquan (common commands)

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");

Other
1, the error message before the query
Db.getpreverror ();
2. Clear the 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: 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: Select Distict name from UserInfo;

3. Check the record of age = 22
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;
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});
The data columns of the added data are not fixed, depending on the data being added

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

4, Query modification Delete
db.users.findAndModify ({
query: {age: {$gte: +}},
Sort: {Age:-1},
Update: {$set: {name: ' A 2 '}, $inc: {age:2}},
Remove:true
});

Db.runcommand ({findandmodify: "Users",
Query: {age: {$gte: +}},
Sort: {Age:-1},
Update: {$set: {name: ' A2 '}, $inc: {age:2}},
Remove:true
});
Update or remove one of the required parameters; other parameters are optional.

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 (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));});

Some of the commands that you might use:

$ne: Not equal to
$GT: Greater Than
$LT: Less than
$gte: greater than or equal to
$lte: Less than or equal to

Current Date:
New Date (). toLocaleString ();

Number of new users in the day:
Db.user_info.find ({create_time:{$gt: 1440000000, $lt: 1440086400}, group_id:{$ne: ' 0 '}}). Count ();

New group of the day:
Db.user_info.distinct (' group_id ', {create_time:{$gt: 1440000000, $lt: 1440086400}, group_id:{$ne: ' 0 '}});

Number of new groups added today:
Db.user_info.distinct (' group_id ', {create_time:{$gt: 1440000000, $lt: 1440086400}, group_id:{$ne: ' 0 '}}). length;

Latest data of the day:
Db.online_data.find ({update_time:{$gt: 1440000000, $lt: 1440086400}, player_num:{$gt: 0}}). Count ();

Maximum number of people online today:
Db.online_data.find ({update_time:{$gt: 1440000000, $lt: 1440086400}}). sort ({player_num:-1}). Limit (1);

The most recent piece of data:
Db.online_data.find (). Sort ({update_time:-1}). Limit (1);

MongoDB command use Daquan (common commands)