MongoDB remains a powerful tool in 2025, being one of the most popular NoSQL databases. Its flexibility and scalability make it a preferred choice for many developers and data scientists. While working with MongoDB, understanding query operators is crucial for efficient data retrieval and manipulation. This article explores some common MongoDB query operators used in 2025.

What are MongoDB Query Operators?

Query operators in MongoDB are special keywords used to specify conditions in queries. They allow for complex queries and data manipulation by providing a way to filter, sort, and modify documents within a collection.

Common Query Operators

1. $eq - Equals

The $eq operator is used to match documents where the value of a field equals the specified value. It is equivalent to the equality sign in many query languages.

Example:

db.collection.find({ age: { $eq: 25 } });

2. $gt and $lt - Greater Than and Less Than

The $gt operator selects documents where the specified field's value is greater than the given value. Conversely, $lt selects those less than the given value.

Example:

db.collection.find({ score: { $gt: 80 } });
db.collection.find({ score: { $lt: 50 } });

3. $in - In

The $in operator matches any of the values specified in an array. It's useful for checking if a field's value is within a given set.

Example:

db.collection.find({ status: { $in: ["active", "pending"] } });

4. $ne - Not Equals

The $ne operator matches documents where the value of a field is not equal to the specified value.

Example:

db.collection.find({ age: { $ne: 30 } });

5. $and, $or - Logical Operators

Logical operators $and and $or combine multiple conditions. They are essential for constructing complex queries that require multiple conditions.

Example:

db.collection.find({
  $and: [
    { category: "electronics" },
    { price: { $lt: 1000 } }
  ]
});

db.collection.find({
  $or: [
    { status: "active" },
    { age: { $gte: 18 } }
  ]
});

6. $exists - Field Presence

The $exists operator checks for the existence of a field in a document. It is beneficial for filtering documents that either have or lack specific fields.

Example:

db.collection.find({ email: { $exists: true } });

7. $regex - Regular Expressions

The $regex operator performs pattern matching using regular expressions. It's particularly useful for searching text fields.

Example:

db.collection.find({ name: { $regex: /john/i } });

Exploring Further

Beyond these operators, MongoDB in 2025 continues to innovate with features that streamline data operations. To delve deeper into working with MongoDB, here are some resources to explore:

Understanding and mastering these operators is pivotal in executing advanced queries and ensuring the optimal performance of your MongoDB database in 2025.