Geek Slack

MongoDB Tutorial
    About Lesson

    Introduction

    The MongoDB Query API allows you to retrieve and manipulate data from MongoDB databases using various query operators and methods.

    Basic Queries

    Perform basic queries to retrieve documents from a collection:

    Example: Basic Query

    db.collection.find({ "field": value })
    

    Replace collection with your collection name, field with the document field to query, and value with the value to match.

    Query Operators

    Use query operators to specify conditions in MongoDB queries:

    Example: Query with Operator

    db.collection.find({ "age": { $gt: 30 } })
    

    This query finds documents where the “age” field is greater than 30.

    Projection

    Limit fields returned in query results using projection:

    Example: Projection

    db.collection.find({}, { "name": 1, "age": 1 })
    

    This query returns only the “name” and “age” fields from documents in the collection.

    Sorting

    Sort query results based on one or more fields:

    Example: Sorting

    db.collection.find().sort({ "age": 1 })
    

    This query sorts documents in ascending order based on the “age” field.

    Limit and Skip

    Limit and skip results in MongoDB queries:

    Example: Limit and Skip

    db.collection.find().limit(5).skip(10)
    

    This query limits results to 5 documents, skipping the first 10 documents in the collection.

    Conclusion

    Understanding the MongoDB Query API is essential for efficiently querying data from MongoDB databases. With basic and advanced query operations, you can retrieve, manipulate, and analyze data as per your application’s requirements.