How to Find a Specific Document With Array in MongoDB
In MongoDB, a field in a document may contain some more data, something like sub-items.
In this article, we will see how we can search a specific document based on the sub-items of a field. Also, we will see an example relevant to the topic to make it easier.
the find()
Method in MongoDB
We use the built-in method find()
to search specific documents from a collection based on specific criteria. Now, we need to pass a parameter that searches specific elements based on the sub-item array.
The general syntax for the parameter will be:
"field.item" : 'value'
Note: Please check if you are in the right collection. To switch on a specific collection, use the command
use YourCollection
.
Find a Specific Document From a Collection in MongoDB
In our below example, we will illustrate how we can find a document from a collection based on the array of items. But first, let’s consider that we have the below documents in our collection:
{
_id: ObjectId("637524953f80c4973e1f16b6"),
sl: 1,
Name: 'Ron',
List: {
Element_1: 'A',
Element_2: '3'
}
}
{
_id: ObjectId("637524953f80c4973e1f16b7"),
sl: 2,
Name: 'Caron',
List: {
Element_1: 'A',
Element_2: '3'
}
}
As you can see above, the field List
contains an array of items as a sub-item. Now, we will find a specific document based on these sub-items.
Now, the command for this purpose will look like this:
db.mycolletion.find({ "List.Element_1" : "A" })
After running the above command, you will get the below output in your console.
{
_id: ObjectId("637524953f80c4973e1f16b6"),
sl: 1,
Name: 'Ron',
List: {
Element_1: 'A',
Element_2: '3'
}
}
Please note that the commands shown in this article are for the MongoDB database and the command needs to be run on the MongoDB console.
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