MongoDB Common Commands

MongoDB Common commands:

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

Show DBS: Display database list use database name: Switch the current database, which is the same as the meaning of ms-sql inside
Show Collections: Displays a collection in the current database (similar to a table in a relational database)
Db.myCollections.find (): (equivalent to select* from mycollections in SQL) data lookup of the Mycollections collection in the current database.
                       (All data is listed due to no conditions). 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.

Db.myCollections.count (); Query the number of data bars for the current collection. Db.userInfo.find ({name: ' Zhangsan ', age:22}); Search by condition, equivalent to: SELECT * from userInfo where name = ' Zhangsan ' and "age = ' All ';d b.userinfo.find (). Limit (5); Query the first 5 data equivalent: Selecttop 5 * from Userinfo;db.userinfo.find (). Skip (10); Query data after 10, equivalent to: SELECT * from UserInfo where ID not in (select Top ten * from UserInfo);

More detailed commands are as follows:

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");

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 (

Select Top Ten * 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;

If you want to return the number of records after the limit, use count (true) or count (not 0)
Db.users.find (). Skip (. Limit (5). Count (True);

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.collection.update (criteria, objnew, Upsert, Multi)

Criteria:update query conditions, similar to those in the SQL update query

Objnew:update objects and some updated operators (such as $, $inc ... ) and so on, can also be understood as SQL update query within the set after.

Upsert: If there is no record of update, insert objnew,true as INSERT, default is False, do not insert.

Multi:mongodb default is False, only update the first record found, if this parameter is true, the condition is checked out all the records are updated.

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: 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

});

MongoDB Common Commands