MongoDB Common operation Commands Daquan _mongodb

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

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

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

2. Switch/CREATE Database

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

3, query all databases

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Show DBS;

4, delete the current use of the database

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Db.dropdatabase ();

5, clone the database from the designated host

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

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

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

7, repair the current database

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Db.repairdatabase ();

8. View the database currently in use

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Db.getname ();
db DB and GetName methods are the same effect, you can query the currently used database

9, display the current DB status

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Db.stats ();

10, the current DB version

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Db.version ();

11, view the current DB link machine address

Copy Code code as follows:

Db.getmongo ();

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

Copy Code code as follows:

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

2, get the specified name of the aggregation set (table)

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Db.getcollection ("account");

3, get the current db of all the aggregation set

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Db.getcollectionnames ();

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

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Db.printcollectionstats ();

Third, user-related
1. Add a user

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

2. Database Authentication and Safe mode

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

3. Show all current users

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Show Users;

4, delete the user

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Db.removeuser ("UserName");

Aggregate collection Query
1. Check all records

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Db.userInfo.find ();
Equivalent to: select* from UserInfo;

The default display of 20 records per page, when not displayed, you can use it iterative command to query the next page of data. Note: type it command without ";"
But you can set the size of each page to display the data, with dbquery.shellbatchsize= 50, so that each page shows 50 records.
2. Duplicate data for a column in the current clustered collection after the query has been removed

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Db.userInfo.distinct ("name");
Will filter out the same data in name
Equivalent: Select Distict name from UserInfo;

3, Query age = 22 Records

Copy Code code as follows:

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

4. Check the records of age > 22

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

5. Check the records of age < 22

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

6. Check the records of age >= 25

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

7. Check the records of age <= 25

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

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

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

9, query name contains MONGO data

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

10, query name in the beginning of the MONGO

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

11. Query Specify column name, age data

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Db.userInfo.find ({}, {name:1, age:1});
Equivalent to: Select Name, age from UserInfo;

Of course, name can also use True or false, as with ture in the case of river Name:1 effect, if False is excluding name, display column information other than name.
12. Query Specify column name, age data, age > 25

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

13. Sort by age

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

14, Query name = Zhangsan, age = 22 data

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

15, query the first 5 data

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

16, query 10 after the data

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

17, the query in the data between 5-10

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

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

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

19, query the first piece of data

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

20, query a result set of the number of records

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

21, according to a column to sort

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

Five, index
1. CREATE index

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

2. Querying all indexes of the current aggregation collection

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Db.userInfo.getIndexes ();

3. View the total index record size

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Db.userInfo.totalIndexSize ();

4. Read all index information for the current collection

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Db.users.reIndex ();

5, delete the specified index

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Db.users.dropIndex ("Name_1");

6. Delete all index indexes

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Db.users.dropIndexes ();

Vi. modifying, adding, and deleting collection data
1, add

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

The data column of the added data, not fixed, according to the added data
2, modify

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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: 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

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

4, query Modify Delete

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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 the necessary parameters; Other parameters are optional.
Parameter detailed default value
Query filter Criteria {}
Sort if more than one document conforms to the query filtering criteria, the first-ranked object will be selected in the arrangement specified by the parameter, and the object will be manipulated {}
If remove is true, the selected object will be deleted before it returns N/A
Update a Modifier object
N/A
If new is true, the modified object is returned instead of the original object.    In a delete operation, this 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
VII. Statement block operations
1, simple Hello World

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Print ("Hello world!");

This type of writing invokes the print function, and writes directly to "Hello world!" The effect is the same;
2. Convert an object to JSON

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

3. Recycle Add Data

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

This allows you to add 30 of data to the loop, but also omit the notation of parentheses.

Copy Code code 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 Db.users.find () query, display more than one page of data, you can use it to view the next page of information;
4, Find cursor query

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

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

Copy Code code as follows:

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

You can also omit the {} number
5. Foreach Iterative cycle

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

foreach must pass a function to handle the data information for each iteration
6, the Find cursor when the array processing

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var cursor = Db.users.find ();
CURSOR[4];

Get the data for the subscript index of 4
Since it can be treated as an array, it can be obtained in length: Cursor.length () or cursor.count ();
So we can also use the loop to display the data.

Copy Code code as follows:

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

7. Convert find cursor to array

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> var arr = db.users.find (). ToArray ();
> Printjson (arr[2]);

Convert it to an array by using the ToArray method
8. Customize our own query results
Show only age <= 28 and show only age this column of data

Copy Code code as follows:

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

Exclude an Age column

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

9, the foreach transfer function display information

Copy Code code as follows:

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

Viii. Other
1, the error message before the query

Copy Code code as follows:

Db.getpreverror ();

2. Clear Error Record

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Db.reseterror ();

To view the basic information of a clustered collection
1, see Help Db.yourColl.help ();
2, query the current set of data bar number Db.yourColl.count ();
3, view the size of the data Space db.userInfo.dataSize ();
4. Get the DB Db.userInfo.getDB () where the current aggregation set is located;
5, get the current aggregation state db.userInfo.stats ();
6, get the aggregate aggregate size db.userInfo.totalSize ();
7, the aggregation set storage space size db.userInfo.storageSize ();
8, shard version information Db.userInfo.getShardVersion ()
9, gather the collection to rename Db.userInfo.renameCollection ("Users"); Rename UserInfo to users
10, delete the current aggregation set Db.userInfo.drop ();

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Show DBS: Displaying a list of databases
Show Collections: Displays the collection in the current database (similar to tables in a relational database)
Show Users: displaying user
Use <db name>: Toggle the current database, which is the same as in Ms-sql.
Db.help (): Display database operation commands, there are a lot of commands
Db.foo.help (): Displays the set Operation command, also has a lot of commands, Foo refers to the current database, a collection called Foo, not the true 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}): Finds a collection of Foo in the current database, provided that one of the properties in the data is called a, and A has a value of 1