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Query Documents

On this page

  • Read All Documents in a Collection
  • Specify Equality Condition
  • Specify Conditions Using Query Operators
  • Specify Logical Operators (AND / OR)
  • Read Behavior
  • Additional Query Tutorials

Use the db.collection.find() method in the MongoDB Shell to query documents in a collection.

The examples on this page reference the Atlas sample dataset. You can create a free Atlas cluster and populate that cluster with sample data to follow along with these examples. To learn more, see Get Started with Atlas.

Read All Documents in a Collection

To read all documents in the collection, pass an empty document as the query filter parameter to the find method. The query filter parameter determines the select criteria.

Example

To return all documents from the sample_mflix.movies collection:

use sample_mflix
db.movies.find()

This operation is equivalent to the following SQL statement:

SELECT * FROM movies

Specify Equality Condition

To select documents which match an equality condition, specify the condition as a <field>:<value> pair in the query filter document.

Example

To return all movies where the title equals Titanic from the sample_mflix.movies collection:

use sample_mflix
db.movies.find( { "title": "Titanic" } )

This operation corresponds to the following SQL statement:

SELECT * FROM movies WHERE title = "Titanic"

Specify Conditions Using Query Operators

Use query operators in a query filter document to perform more complex comparisons and evaluations. Query operators in a query filter document have the following form:

{ <field1>: { <operator1>: <value1> }, ... }

Example

To return all movies from the sample_mflix.movies collection which are either rated PG or PG-13:

use sample_mflix
db.movies.find( { rated: { $in: [ "PG", "PG-13" ] } } )

This operation corresponds to the following SQL statement:

SELECT * FROM movies WHERE rated in ("PG", "PG-13")

Note

Although you can express this query using the $or operator, use the $in operator rather than the $or operator when performing equality checks on the same field.

Specify Logical Operators (AND / OR)

A compound query can specify conditions for more than one field in the collection's documents. Implicitly, a logical AND conjunction connects the clauses of a compound query so that the query selects the documents in the collection that match all the conditions.

Example

To return movies which were released in Mexico and have an IMDB rating of at least 7:

use sample_mflix
db.movies.find( { countries: "Mexico", "imdb.rating": { $gte: 7 } } )

Use the $or operator to specify a compound query that joins each clause with a logical OR conjunction so that the query selects the documents in the collection that match at least one condition.

Example

To return movies from the sample_mflix.movies collection which were released in 2010 and either won at least 5 awards or have a genre of Drama:

use sample_mflix
db.movies.find( {
     year: 2010,
     $or: [ { "awards.wins": { $gte: 5 } }, { genres: "Drama" } ]
} )

Read Behavior

To learn more about the specific behavior of reading documents, see Behavior.

Additional Query Tutorials

For additional query examples, see:

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