MongoDB - Comparison Query Operators

In MongoDB, comparison query operators enable users to filter documents according to specific conditions. They allow you to match, exclude, or select records within a range of values, making it easier to query and retrieve documents based on numerical, string, or date field comparisons. These operators help refine search queries and improve performance.

Below is a list of commonly used MongoDB comparison query operators:

MongoDB Comparison Operator Examples

For better understanding, let’s look at real-world examples using a sample "contributor" collection in a database named "GeeksforGeeks".

• Database: GeeksforGeeks
• Collection: contributor
• Document: three documents that contain the details of the contributors in the form of field-value pairs.

Example 1: Using $nin operator:

In this example, we are retrieving only those employee’s documents whose name is not "Amit" or "Suman".

Query:

 db.contributor.find({name: {$nin: ["Amit", "Suman"]}}).pretty()

Output

Example 2: Using $in operator

In this example, we are retrieving only those employee's documents whose name is either "Amit" or "Suman".

Query:

db.contributor.find({name: {$in: ["Amit", "Suman"]}}).pretty()

Output:

Example 3: Using $lt operator

In this example, we are selecting those documents where the value of the salary field is less than 2000.

Query:

db.contributor.find({salary: {$lt: 2000}}).pretty()

Output:

Example 4: Using $eq operator

In this example, we are selecting those documents where the value of the branch field is equal to "CSE".

Query:

 db.contributor.find({branch: {$eq: "CSE"}}).pretty()

Output:

Example 5: Using $ne operator

In this example, we are selecting those documents where the value of the branch field is not equal to CSE.

Query:

 db.contributor.find({branch: {$ne: "CSE"}}).pretty()

Output:

Example 6: Matching values using $gt operator:

In this example, we are selecting those documents where the value of the salary field is greater than 1000.

Query:

db.contributor.find({salary: {$gt: 1000}}).pretty()

Output:

Example 7: Using $gte operator

In this example, we are selecting those documents where the value of the joiningYear field is greater than equals to 2017.

Query:

db.contributor.find({joiningYear: {$gte: 2017}})

Output:

Example 8: Using $lte operator

In this example, we are selecting those documents where the value of the salary field is less than equals to 1000.

Query:

db.contributor.find({salary: {$lte: 1000}}).pretty()

Output: