MongoDB : Mangodb Find

1. MongoDB Find Operations

Definition

The find() method in MongoDB is used to query documents from a collection. It allows you to retrieve documents that match specific criteria and supports various query operators for complex searches. The find operation is fundamental for data retrieval in MongoDB.

Algorithm 1: Basic Find Query :-

Step 1: Connect to MongoDB database

Step 2: Select the collection

Step 3: Define query criteria

Step 4: Execute find() operation

Step 5: Process results

Example 1: Simple Find Query

// Find all students with age greater than 20

db.students.find({

  age: { $gt: 20 }

})

Algorithm 2: Find with Multiple Conditions :-

Step 1: Define multiple criteria

Step 2: Use logical operators

Step 3: Add query operators

Step 4: Specify projections if needed

Step 5: Execute complex query

Example 2: Complex Find Query

// Find documents with multiple conditions

db.products.find({

  $and: [

    { price: { $gte: 100 } },

    { category: "electronics" },

    { inStock: true }

  ]

})

Algorithm 3: Find with Projection :-

Step 1: Define search criteria

Step 2: Specify fields to include/exclude

Step 3: Set projection parameters

Step 4: Apply sorting if needed

Step 5: Execute find with projection

Example 3: Find with Projection

// Find with specific field projection

db.users.find(

  { age: { $gt: 25 } },

  {

    name: 1,

    email: 1,

    _id: 0

  }

).sort({ name: 1 })