- Reference >
- Operators >
- Query and Projection Operators >
- Element Query Operators >
- $exists
$exists¶
On this page
Definition¶
-
$exists
¶ Syntax:
{ field: { $exists: <boolean> } }
When
<boolean>
is true,$exists
matches the documents that contain the field, including documents where the field value isnull
. If<boolean>
is false, the query returns only the documents that do not contain the field.MongoDB $exists does not correspond to SQL operator
exists
. For SQLexists
, refer to the$in
operator.
See also
$nin
, $in
, and
How do I query for fields that have null values?.
Examples¶
Exists and Not Equal To¶
Consider the following example:
This query will select all documents in the inventory
collection
where the qty
field exists and its value does not equal 5
or
15
.
Null Values¶
Given a collection named records
with the following documents:
Consider the output of the following queries:
Query:
Result:
Query:
Result:
Query:
Result: