MongoDB $and Operator

What You’ll Learn

The $and operator combines multiple conditions with logical AND. Every expression must be true for the result to pass. Use it in find(), $match, and aggregation expressions when you need explicit multi-condition logic.

Definition and Usage

In MongoDB, the $and operator performs a logical AND on an array of expressions. In a query, documents must satisfy every condition inside $and. In an aggregation expression, $and returns true only when all sub-expressions evaluate to true.

📝 Syntax

The $and operator takes an array of two or more expressions:

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

Query Example (in $match or find)

{ $and: [
  { price: { $gte: 100 } },
  { inStock: true }
] }

Aggregation Expression Example (in $project)

{ $and: [
  { $gte: [ "$age", 18 ] },
  { $eq: [ "$active", true ] }
] }

Syntax Rules

• Array required — always wrap conditions in square brackets.
• Minimum two expressions — otherwise use a single condition directly.
• In $match, use field-based conditions directly inside $and.
• For field-to-value comparisons in $match, wrap with $expr.
• Returns false if any sub-expression is false (aggregation mode).

Examples Gallery

Combine multiple conditions in queries, filter pipelines with $match, and compute boolean flags with $project.

[
  { "_id": 1, "name": "Laptop",  "price": 899,  "inStock": true,  "category": "electronics" },
  { "_id": 2, "name": "Mouse",   "price": 25,   "inStock": true,  "category": "electronics" },
  { "_id": 3, "name": "Desk",    "price": 350,  "inStock": false, "category": "furniture" },
  { "_id": 4, "name": "Monitor", "price": 220,  "inStock": true,  "category": "electronics" }
]

db.products.aggregate([
  {
    $match: {
      $and: [
        { category: "electronics" },
        { inStock: true },
        { price: { $gte: 100 } }
      ]
    }
  },
  {
    $project: {
      name: 1,
      price: 1,
      category: 1
    }
  }
])

{ "name": "Laptop",  "price": 899, "category": "electronics" }
{ "name": "Monitor", "price": 220, "category": "electronics" }

db.products.aggregate([
  {
    $match: {
      $and: [
        { price: { $gte: 100 } },
        { price: { $lte: 500 } }
      ]
    }
  }
])

// Matches products with price between 100 and 500 (inclusive)
// Desk (350), Monitor (220)

db.orders.aggregate([
  {
    $match: {
      $expr: {
        $and: [
          { $gte: [ "$total", 100 ] },
          { $lte: [ "$total", "$budget" ] },
          { $eq: [ "$status", "pending" ] }
        ]
      }
    }
  }
])

// Returns pending orders where:
// total >= 100 AND total <= budget

db.users.aggregate([
  {
    $project: {
      name: 1,
      age: 1,
      active: 1,
      score: 1,
      isEligible: {
        $and: [
          { $gte: [ "$age", 18 ] },
          { $eq: [ "$active", true ] },
          { $gte: [ "$score", 80 ] }
        ]
      }
    }
  }
])

// Alice: age 25, active true,  score 85 → isEligible: true
// Bob:   age 17, active true,  score 92 → isEligible: false
// Carol: age 30, active false, score 78 → isEligible: false

🚀 Use Cases

• Product search — combine category, price range, and availability filters.
• User eligibility — check age, account status, and score thresholds together.
• Order validation — ensure status, amount, and budget rules all pass.
• Reporting flags — add computed yes/no fields with $project and $and.

💡 Best Practices