MongoDB Common operations Go

Øcollection 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 ();

Ø 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");

Ø Other

1, the error message before the query

Db.getpreverror ();

2. Clear the Error Record

Db.reseterror ();

Three, collection aggregation set operation

Ø View Aggregate Collection basic information

1. View Help

Db.yourColl.help ();

2 . Query the number of data bars in the current collection

Db.yourColl.count ();

3. View data space size

Db.userInfo.dataSize ();

4. Get the db where the current aggregation collection resides

Db.userInfo.getDB ();

5. Get the current aggregation status

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. Clustered Collection Rename

Db.userInfo.renameCollection ("users");

Rename UserInfo to users

10. Delete the current aggregation collection

Db.userInfo.drop ();

Ø Aggregation 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 ";"

However, you can set the size of the data displayed on each page, using Dbquery.shellbatchsize = 50, so that 50 records per page are displayed.

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 age > 22;

5. Check the records of age < 22

Db.userInfo.find ({age: {$lt: 22}});

Equivalent to: SELECT * from UserInfo where age < 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: Select Top 5 * from UserInfo;

16, the query 10 after the data (starting from the 11th article

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: SELECT top 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;

Ø 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 ();

Ø 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.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 ({

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

    Remove:true

});

    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

Ø 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 ();

}

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));});

As described above, foreach needs to pass a function that takes a parameter, that is, the object that is currently looping, and then processes the incoming parameter information in the function weight.

Transferred from: http://www.cnblogs.com/hoojo/archive/2011/06/01/2066426.html

MongoDB Common operations Go