$gt (aggregation)

Definition

$gt

Compares two values and returns:

• true when the first value is greater than the second value.
• false when the first value is less than or equal to the second value.

The $gt compares both value and type, using the specified BSON comparison order for values of different types.

$gt has the following syntax:

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

For more information on expressions, see Expressions.

Example

Create an inventory collection with these documents:

db.inventory.insertMany( [
   { _id : 1, item : "abc1", description: "product 1", qty: 300 },
   { _id : 2, item : "abc2", description: "product 2", qty: 200 },
   { _id : 3, item : "xyz1", description: "product 3", qty: 250 },
   { _id : 4, item : "VWZ1", description: "product 4", qty: 300 },
   { _id : 5, item : "VWZ2", description: "product 5", qty: 180 }
] )

Use the $gt operator to determine if qty is greater than 250:

db.inventory.aggregate(
   [
     {
       $project:
          {
            item: 1,
            qty: 1,
            qtyGt250: { $gt: [ "$qty", 250 ] },
            _id: 0
          }
     }
   ]
)

The operation returns the following results:

{ item : "abc1", qty : 300, qtyGt250 : true }
{ item : "abc2", qty : 200, qtyGt250 : false }
{ item : "xyz1", qty : 250, qtyGt250 : false }
{ item : "VWZ1", qty : 300, qtyGt250 : true }
{ item : "VWZ2", qty : 180, qtyGt250 : false }