Sage-Tips

How do I find a specific field in MongoDB?

You can select a single field in MongoDB using the following syntax: db. yourCollectionName. find({“yourFieldName”:yourValue},{“yourSingleFieldName”:1,_id:0});

How do I find one record in MongoDB?

MongoDB – FindOne() Method. The findOne() method finds and returns one document that matches the given selection criteria. If multiple documents satisfy the given query expression, then this method will return the first document according to the natural order which reflects the order of documents on the disk.

What is query in MongoDB?

MongoDB Query is a way to get the data from the MongoDB database. While performing a query operation, one can also use criteria or conditions which can be used to retrieve specific data from the database. MongoDB provides the function names as db. collection_name. find() to operate query operation on database.

How does MongoDB query work?

These queries are sent to the MongoDB server present in the Data Layer. Now, the MongoDB server receives the queries and passes the received queries to the storage engine. MongoDB server itself does not directly read or write the data to the files or disk or memory.

How do I return a specific field in MongoDB?

You can return specific fields in an embedded document. Use the dot notation to refer to the embedded field and set to 1 in the projection document….The following example returns:

1. The _id field (returned by default),
2. The item field,
3. The status field,
4. The uom field in the size document.

How do you query a compass?

1. In Compass, use the left navigation panel to select the database and the collection you want to import the data to.
2. Click the Documents tab.
3. Click Add Data and select Insert Document.
4. Ensure that View is set to JSON, or {} , and paste the copied JSON documents in the field.
5. Click Insert.

How do I export query results in MongoDB?

How to Export MongoDB Query Results to a CSV File

1. Syntax. The syntax for mongoexport goes like this: mongoexport –collection=
2. Example.
3. Check the Exported File.
4. Export Less Fields.
5. Remove Column Headers.
6. Use a File for the Field Names.
7. Changing the Column Order.
8. Access Control/Authentication.

Which query is used to read exactly one document from MongoDB?

Find method in MongoDB Query is used to fetch a particular document from the MongoDB collection.

What MongoDB command can you use to view existing collections within a database?

Use show collections command from MongoDB shell to list all collections created in the current database.

Which of the following method is used to query documents in collection?

Explanation: The find() method with no parameters returns all documents from a collection and returns all fields for the documents. Sanfoundry Global Education & Learning Series – MongoDB.