$or Operator - (MongoDB Misc)

The $or operator is a query operator in MongoDB that allows you to perform logical OR operation on an array of two or more expressions. In this page, we will discuss how to use the $or operator in MongoDB.

Syntax

The syntax for using the $or operator in MongoDB is as follows:

{ $or: [ { <expression1> }, { <expression2> }, ... , { <expressionN> } ] }

Example

Let's say you have a collection of employees that contain documents with the following structure:

{
    "name": "John Doe",
    "age": 38,
    "department": "Sales",
    "isManager": true
}

You want to perform a query that returns all the employees who are either in the Sales department or are a manager. Here is an example of how to use the $or operator to achieve this:

db.employees.find(
    {
        $or: [
            { department: "Sales" },
            { isManager: true }
        ]
    }
)

This query will return all the employees who either belong to the Sales department or are managers.

Output

The output of the above query will depend on the data in the employees collection. It will return all the documents in the collection where the department field is "Sales" or the isManager field is true.

Explanation

The $or operator in MongoDB is used to perform logical OR operations on an array of two or more expressions. It returns true if any of the expressions in the array is true.

In the above example, we used the $or operator to query the employees collection for documents where the department field is "Sales" or the isManager field is true.

Use

The $or operator is useful when you need to perform logical OR operations on multiple expressions in a query. It is also useful when you need to combine two or more conditions in a query such that the result is true when any one of the conditions is true.

A common use case for the $or operator is in complex search queries where you need to filter out documents based on multiple criteria.

Important Points

• The $or operator is used to perform logical OR operations on an array of two or more expressions.
• It returns true if any of the expressions in the array is true.
• The $or operator is useful for combining two or more conditions in a query.

Summary

In this page, we discussed the syntax, example, output, explanation, use, and important points of the $or operator in MongoDB. The $or operator is useful when you need to combine two or more conditions in a query and filter out documents based on multiple criteria.