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$ne (aggregation)

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  • Definition
  • Example
$ne

Compares two values and returns:

  • true when the values are not equivalent.

  • false when the values are equivalent.

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

$ne has the following syntax:

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

For more information on expressions, see Expression Operators.

Consider an inventory collection with the following documents:

{ "_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 }

The following operation uses the $ne operator to determine if qty does not equal 250:

db.inventory.aggregate(
[
{
$project:
{
item: 1,
qty: 1,
qtyNe250: { $ne: [ "$qty", 250 ] },
_id: 0
}
}
]
)

The operation returns the following results:

{ "item" : "abc1", "qty" : 300, "qtyNe250" : true }
{ "item" : "abc2", "qty" : 200, "qtyNe250" : true }
{ "item" : "xyz1", "qty" : 250, "qtyNe250" : false }
{ "item" : "VWZ1", "qty" : 300, "qtyNe250" : true }
{ "item" : "VWZ2", "qty" : 180, "qtyNe250" : true }
←  $multiply (aggregation)$not (aggregation) →

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