Querying MongoDB to match in the first item in an array

Question

I\'m aware of the $in operator, which appears to search for an item\'s presence in array, but I only want to find a match if the item is in the first position i

Answer 1

You can use dot notation for array indexes:

db.products.find({"imgs.0": "http://foo.jpg"})

Here is an excerpt from the relevant documentation for dot notation.

MongoDB uses the dot notation to access the elements of an array and to access the fields of a subdocument.

To access an element of an array by the zero-based index position, concatenate the array name with the dot (.) and zero-based index position, and enclose in quotes:

'<array>.<index>'

Additionally, here is a link to the relevant array documentation.

Answer 2

I believe you want imgs.0. eg, given your example document, you want to say: db.products.find({"imgs.0": "http://foo.jpg"})

Be aware that referencing array indexes only works for the first-level array. Mongo doesn't support searching array indexes any deeper.