Introduction to MongoDB $lt Operator

MongoDB is a NoSQL database that supports various query operations. In MongoDB, the $lt operator is used to query documents where a field is less than a certain value.

Syntax

The $lt operator is used in the following syntax:

{ <field>: { $lt: <value> } }

Where <field> represents the field name and <value> represents the value to compare.

Use Cases

The $lt operator can be used in various scenarios, such as:

• Querying documents where a field is less than a certain value.
• Combining with other operators for complex queries.

Examples

Example 1: Querying users under 18 years old

Suppose we have a collection named “users” that contains information about users, including user ID, name, age, etc. We want to query users who are under 18 years old using the $lt operator:

db.users.find({ age: { $lt: 18 } })

After running this command, MongoDB will return all user records who are under 18 years old.

Example 2: Querying orders with amount less than 500

Suppose we have a collection named “orders” that contains information about orders, including order ID, order date, order status, order amount, etc. We want to query orders with amount less than 500 using the $lt operator:

db.orders.find({ amount: { $lt: 500 } })

After running this command, MongoDB will return all order records with amount less than 500.

Conclusion

The $lt operator is a commonly used operator in MongoDB for querying documents where a field is less than a certain value. It can be combined with other operators for more complex queries.