How do I delete a file in MongoDB?

remove() method is used to remove documents from a collection. Specifies deletion criteria using query operators. To delete all documents in a collection, pass an empty document ({}). To limit the deletion to just one document, set to true.

To delete a record, or document as it is called in MongoDB, we use the deleteOne() method. The first parameter of the deleteOne() method is a query object defining which document to delete. Note: If the query finds more than one document, only the first occurrence is deleted.

Similarly, what is collection MongoDB? A grouping of MongoDB documents. A collection is the equivalent of an RDBMS table. A collection exists within a single database. Collections do not enforce a schema. Documents within a collection can have different fields.

Also asked, how do I remove all records from a collection in MongoDB?

  1. Delete All Documents. To remove all documents from a collection, pass an empty filter document {} to either the db.
  2. Delete All Documents that Match a Condition. To delete all documents that match a deletion criteria, pass a filter parameter to either db.
  3. Remove Only One Document that Matches a Condition.

How do I create a collection in MongoDB?

MongoDB Create Collection

  1. Select a MongoDB database you like to Create a Collection within, using USE command. Following is the syntax of USE command : use <database_name>
  2. Insert a record to Collection, with Collection Name mentioned in the command as shown below db.
  3. View the existing collections using following command show collections.

How do I remove a field from a collection in MongoDB?

In MongoDB, the $unset operator is used to delete a particular field. The value specified in the $unset expression does not make any impact on the operation. The $unset has no effect when the field does not exist in the document. name of the column or field to be deleted.

Is the method used to limit the records in MongoDB?

The Limit() Method To limit the records in MongoDB, you need to use limit() method. The method accepts one number type argument, which is the number of documents that you want to be displayed.

What is capped collection in MongoDB?

We can create collections in mongoDb on which we can apply size limit. These special type of collections are called Capped Collections. These are a kind of circular queues, in which if allocated size limit is reached, it makes space for new documents by overwriting the oldest documents in the collection.

What type of DBMS is MongoDB?

MongoDB is an open source database management system (DBMS) that uses a document-oriented database model which supports various forms of data.

What is MongoDB tutorial?

It is an open-source, cross-platform, document-oriented database written in C++. Our MongoDB tutorial includes all topics of MongoDB database such as insert documents, update documents, delete documents, query documents, projection, sort() and limit() methods, create a collection, drop collection, etc.

Where is MongoDB?

The MongoDB $where operator is used to match documents that satisfy a JavaScript expression. A string containing a JavaScript expression or a JavaScript function can be pass using the $where operator.

How do I delete a Google collection from my phone?

Delete a collection On an Android phone or tablet, open the Google+ app . At the bottom, tap Collections. Tap a collection. Tap More. ?Delete collection. Check the box, then tap Delete.

How do I view collections in MongoDB?

Use show collections command from MongoDB shell to list all collection created in the current database. First, select the database you want to view the collection. Select mydb database and run show collections command to list available collections in MongoDB database.

Which process in MongoDB provides high scalability?

MongoDB supports horizontal scaling through Sharding , distributing data across several machines and facilitating high throughput operations with large sets of data. Sharding allows you to add additional instances to increase capacity when required. In the image above, each shard runs on a different server.

Is the method used to display results in a formatted way?

The pretty() Method To display the results in a formatted way, you can use pretty() method.

Where does MongoDB place its default database directory for datafiles?

MongoDB requires a data folder to store its files. The default location for the MongoDB data directory is c:datadb. So you need to create this folder using the Command Prompt.

Is the method used to display results in a formatted way in MongoDB?

Syntax. As we have mentioned earlier, the MongoDB find method will display all the documents in a non-structured way. Another method we use with our MongoDB find method is the pretty() Method. The pretty() method is used to display the results in a formatted way.

What is a table called in MongoDB?

A table in Oracle is made up of a fixed number of columns for any number of rows. Every row in a table has the same columns. Collection in MongoDB: A collection in MongoDB is made up of documents.

How documents are stored in MongoDB?

In MongoDB, data is stored as documents. These documents are stored in MongoDB in JSON (JavaScript Object Notation) format. JSON documents support embedded fields, so related data and lists of data can be stored with the document instead of an external table. JSON is formatted as name/value pairs.