$ne¶
- $ne¶
Syntax: {field: {$ne: value} }
$ne selects the documents where the value of the field is not equal (i.e. !=) to the specified value. This includes documents that do not contain the field.
For comparison of different BSON type values, see the specified BSON comparison order.
Consider the following example:
db.inventory.find( { qty: { $ne: 20 } } )
This query will select all documents in the inventory collection where the qty field value does not equal 20, including those documents that do not contain the qty field.
Consider the following example which uses the $ne operator with a field in an embedded document:
db.inventory.update( { "carrier.state": { $ne: "NY" } }, { $set: { qty: 20 } } )
This update() operation will set the qty field value in the documents that contain the embedded document carrier whose state field value does not equal “NY”, or where the state field or the carrier embedded document do not exist.
The inequality operator $ne is not very selective since it often matches a large portion of the index. As a result, in many cases, a $ne query with an index may perform no better than a $ne query that must scan all documents in a collection. See also Query Selectivity.