How do I access a collection in MongoDB?

How do I access a collection in MongoDB?

In the mongo shell:

1. To see the list of collections in the current database, use the show collections command:
2. To see the help for methods available on the collection objects (e.g. db. ), use the db..help() method:

What are database collections?

A database is a collection of information that is organized so that it can be easily accessed, managed and updated. Computer databases typically contain aggregations of data records or files, containing information about sales transactions or interactions with specific customers.

What does DB collection find return?

collection. find() returns the cursor of Result Set of a query by which you can iterate over the result set or print all documents.

What is the command used to create a collection inside a database?

createCollection() to create a capped collection, or to create a new collection that uses document validation. db. createCollection() is a wrapper around the database command create .

How do I show all collections in MongoDB?

1. connect with the MongoDB database using mongo . This will start the connection.
2. then run show dbs command. This will show you all exiting/available databases.
3. then select the database you want. In the above it is anuradhfirst .
4. then run show collections command.

How do I find my MongoDB database?

Use show dbs command from mongo shell to list all the available databases on MongoDB server. This will show the database name with there size. You can select any database using the use statement and work on it.

How do I show all files in a collection in MongoDB?

step 1: Enter into the MongoDB shell. step 2: for the display all the databases. step 4: for statistics of your database. step 5: listing out all the collections(tables).

How do I list all collections in MongoDB?

1. connect with the MongoDB database using mongo . This will start the connection.
2. then select the database you want. In the above it is anuradhfirst . Then run use anuradhfirst . This will switch to the database you want.
3. then run show collections command. This will show all the collections inside your selected database.

Does MongoDB automatically create collections?

MongoDB creates collections automatically when you insert some documents. For example: Insert a document named seomount into a collection named SSSIT. The operation will create the collection if the collection does not currently exist. If you want to see the inserted document, use the find() command.

How to retrieve elements from a collection in Java?

ListIterator Interface: It is an interface that contains methods to retrieve the elements from a collection object, both in forward and reverse directions. This iterator is for list based collections.

How is cursor used to retrieve data from collection?

Cursor is an interface and it is used to retrieve data from collection object,one by one. Cursor has 3 types, which are given below: Iterator Interface: Iterator is an interface provided by collection framework to traverse a collection and for a sequential access of items in the collection.

How to retrieve documents from a collection in MongoDB?

To understand the above syntax, let us create a collection with documents. The query to create documents are as follows: Now you can use the above syntax in order to retrieve all the documents from a collection with the help of find () method.

How to retrieve 2 million records from a database in Java?

There is a database it contains 2 million records approx in a table . and i ran the query from my java code like this ” select * from table” . will it fetch the complete data from the database in the result set . or not . If yes then how it will work i want to learn the working on this retrieveal ,