Mongo DB Query Cheat Sheet

Mongo Query cheat Sheet 

1. mongo  --  start mongo shell

(By default, mongo looks for a database server listening on port 27017 on the localhost interface.
To connect to a server on a different port or interface, use the --port and --host options.) 

2. List all the database in mongo 

show dbs

3. To create a new database 
 Use %database name%
(but the db hasn’t been created.Now insert some data into collection then it will show the data) 

use test   ( test is the default name of the database which already exist in mongo )

5. To list all the tables(collections) within the same db .

show collections

6. To find a particular entry from the collection 

db.%collection_name%.findOne()

db.testdata.findOne()

7. To find record with where statement and And

Db.%collection_name%.findOne({“key”:”value”,”key”:”value”})

Db.testdata.fineOne({“x”:2})

8. To get the count

Db.%collection_name%.findOne({“key”:”value”,”key”:”value”}).count()

Db.testdata.find().count()

Db.testdata.findOne({“x”:2,”x”:3}).count()

9.To insert multiple documents in mongo table

for (var i = 1; i <= 25; i++) db.%collection_name%.insert( { x : i } ) 

for (var i = 1; i <= 25; i++) db.testData.insert( { x : i } ) 

10. To insert single document in mongo table 

db.%collection_name%.insert( { x : i } )

11. To copy from 1 collection to another

db.source.copyTo("target");

db.testdata.copyTo("testdata1");   
(it will create a new collection with exact no of records
Because copyTo() uses eval internally, the copy operations will block all other operations on the mongod  instance). 

12. Update single document in collection

db.%collection_name%.update( { “search_key” : “search_value” }, { $set : { “update_key” : “update_value” } } )

db.testdata.update({“x”:2}),{$set:{“x”:”300”}})

13. Update Multiple documents in collection 
Db%collection.name%.update({"search_key":"search_value"},{$set:{"update_key":"update_value"}},{"multi":true})
db.testdata.update({"x":3},{"x":"200"}},{"multi":true})

14. Delete document(records) from collection 

db.%collection_name%.remove( { “search_key” : “search_value” } )

db.testdata.remove({"x":2,"x1":100});

15. List all index for a database 

db.system.indexes.find()

16 . List all index in collection 

db.testdata.getIndexes()