MongoDB $gt Operator

What You’ll Learn

The $gt operator checks whether one value is greater than another. Use it in $match to filter documents above a threshold, or in expression stages like $project and $cond to compare fields and get a true/false result.

Definition and Usage

In MongoDB, the $gt operator tests whether one value is strictly greater than another. In a $match stage, { score: { $gt: 80 } } filters documents where score is greater than 80. In an aggregation expression, { $gt: [ "$salary", 50000 ] } returns true or false for each document. It is one of the core comparison operators alongside $gte, $lt, and $lte.

📝 Syntax

$gt has two forms depending on where you use it:

Query form (in $match or find filters)

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

Aggregation expression form (in $project, $cond, etc.)

{ $gt: [ <expression1>, <expression2> ] }

Syntax Rules

• Query form — filters documents where the field is greater than the given value.
• Expression form — compares two expressions and returns true or false.
• Strictly greater than — equal values return false (use $gte to include equals).
• Works with numbers, dates, and strings (BSON comparison order).
• Use expression form inside $project, $addFields, $cond, and $filter.

Examples Gallery

Walk through sample student data, filter high scores with $match, and compare fields with the expression form.

[
  { "_id": ObjectId("609c26812e9274a86871bc6a"), "name": "Alice", "score": 85 },
  { "_id": ObjectId("609c26812e9274a86871bc6b"), "name": "Bob", "score": 70 },
  { "_id": ObjectId("609c26812e9274a86871bc6c"), "name": "Charlie", "score": 95 }
]

db.students.aggregate([
  {
    $match: {
      score: { $gt: 80 }
    }
  }
])

{ "_id": ObjectId("609c26812e9274a86871bc6a"), "name": "Alice", "score": 85 }
{ "_id": ObjectId("609c26812e9274a86871bc6c"), "name": "Charlie", "score": 95 }

db.products.find({
  price: { $gt: 100 }
})

// Returns all products where price > 100
// price: 150  → included
// price: 99   → excluded
// price: 100  → excluded (not strictly greater)

db.employees.aggregate([
  {
    $project: {
      name: 1,
      salary: 1,
      isHighEarner: {
        $gt: [ "$salary", 50000 ]
      }
    }
  }
])

// salary: 60000 → isHighEarner: true
// salary: 45000 → isHighEarner: false
// salary: 50000 → isHighEarner: false

db.students.aggregate([
  {
    $project: {
      name: 1,
      score: 1,
      performance: {
        $cond: [
          { $gt: [ "$score", 80 ] },
          "Excellent",
          "Needs Improvement"
        ]
      }
    }
  }
])

🚀 Use Cases

• Performance evaluation — find students, employees, or products above a score or price threshold.
• Threshold monitoring — detect values exceeding limits in system metrics or quality control.
• Date filtering — select records created after a specific date using { createdAt: { $gt: date } }.
• Conditional logic — use as the if condition inside $cond for tiered labels and bonuses.

💡 Best Practices