MongoDB-Query deeply nested array containing a specific value

Today in this article, we will see how to MongoDB-Query deeply nested array containing a specific value.

Today in this article, we will cover below aspects,

We will cover below a few specific scenarios like dealing with [] array type elements,

• Get documents based on matching nested array size i.e where array size is greater or less than of given specified size.

• Find the array that contains specific values only.

• Specify conditions for array elements.

Sample schema as below,

In the above example, we have two nested arrays Example Books [] and Category [].

MongoDB – Find document from Nested array element

Command

Nested 3 array pattern,

{ <array-field1>.<array-field2>.<array-field3>.<Field-Name>: {<value> }

The below example shows an array filter where we get the list of documents where the value of a nested array element i.e category [] is equal to the value specified.

{'Books.category.key': 'test2-1'}

Example

MongoDB – Find documents by nested array length

Command

{ <array-field1>.<array-field2: {$size :<size-specified> }

Example

The below example shows an array filter where we get the list of documents based on array size i.e category [] size is equal to the size specified.

{'Books.category': {$size:2}}

MongoDB – Find a document with a nested array by specifying multiple conditions

Example

MongoDB query array with fields that contains a given string,

{'Books.category.key': {$regex: '-'}}

Above query returns records where array element “Key” attribute has a value that matches or contains “-“.

References: MongoDB Naming Standards and Guidelines

Do you have any comments or ideas or any better suggestions to share?

Please sound off your comments below.

Happy Coding !!

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