Docs Home → Develop Applications → MongoDB Manual
Query an Array
On this page
You can query arrays in MongoDB using the following methods:
Your programming language's driver.
The MongoDB Atlas UI. To learn more, see Query an Array with MongoDB Atlas.
➤ Use the Select your language drop-down menu in the upper-right to set the language of the following examples or select MongoDB Compass.
Match an Array
The following example queries for all documents where the field tags
value is an array with exactly two elements, "red"
and "blank"
,
in the specified order:
If, instead, you wish to find an array that contains both the elements
"red"
and "blank"
, without regard to order or other elements in
the array, use the $all
operator:
Query an Array for an Element
The following example queries for all documents where tags
is an
array that contains the string "red"
as one of its elements:
For example, the following operation queries for all documents where the array
dim_cm
contains at least one element whose value is greater than
25
.
Specify Multiple Conditions for Array Elements
When specifying compound conditions on array elements, you can specify the query such that either a single array element meets these condition or any combination of array elements meets the conditions.
Query an Array with Compound Filter Conditions on the Array Elements
The following example queries for documents where the dim_cm
array
contains elements that in some combination satisfy the query
conditions; e.g., one element can satisfy the greater than 15
condition and another element can satisfy the less than 20
condition, or a single element can satisfy both:
Query for an Array Element that Meets Multiple Criteria
Use $elemMatch
operator to specify multiple criteria on the
elements of an array such that at least one array element satisfies all
the specified criteria.
The following example queries for documents where the dim_cm
array
contains at least one element that is both greater than ($gt
)
22
and less than ($lt
) 30
:
Query for an Element by the Array Index Position
Using dot notation, you can specify query conditions for an element at a particular index or position of the array. The array uses zero-based indexing.
Note
When querying using dot notation, the field and nested field must be inside quotation marks.
The following example queries for all documents where the second
element in the array dim_cm
is greater than 25
:
Query an Array by Array Length
Use the $size
operator to query for arrays by number of
elements. For example, the following selects documents where the array
tags
has 3 elements.
Query an Array with MongoDB Atlas
The example in this section uses the sample movies dataset. To learn how to load the sample dataset into your MongoDB Atlas deployment, see Load Sample Data.
To query an array in MongoDB Atlas, follow these steps:
Specify a query filter document.
To query a document that contains an array,
specify a query filter document.
A query filter document uses query operators to specify search conditions.
Use the following example documents to query array fields in the
sample_mflix.movies
collection.
To apply a query filter, copy an example document into the Filter search bar and click Apply.
Additional Query Tutorials
For additional query examples, see: