spring mongodb - How to provide match condition to check for empty array using spring data mongodb api?

Question

how to perform below operation (it is the actual mongo query) using MatchOperation in Spring data mongodb ?

$match: { "docs": { $ne: [] } }

here docs is an array field and want to check that it is not empty.

Bertine

Possible duplicate of how to search the array with no empty value from mongodb in java? – Unloosen

I want to perfrom this using spring data's query criteria, not direclty on BasicDBObject – Bertine

Here you go Aggregation aggregation = Aggregation.newAggregation( Aggregation.match(Criteria.where("docs").exists(true))); – Unloosen

it checks for the presence of the field (which in this case do exists) not the value of the field which is empty – Bertine

Something like Aggregation aggregation = Aggregation.newAggregation(Aggregation.match(Criteria.where("docs").ne(Collections.EMPTY_LIST))); – Unloosen

Criteria.where("docs").not().size(0); – Faradism

Thanks Veeram, that worked. – Bertine

I tried both options Criteria.where("docs").not().size(0) & Criteria.where("docs").ne(Collections.EMPTY_LIST) . but its not working, however if I use the same query generated on console, then I can see proper data, strange!! @Bertine can you plz tell which one you implemented – Religieuse

it is too late but I did end up using Aggregation aggregation = Aggregation.newAggregation(Aggregation.match(Criteria.where("docs").ne(Collections.EMPTY_LIST))); – Bertine

Answer 1

I also had a similar problem, but I solved is as below.

MatchOperation mathOpertaion = match(Criteria.where("docs") .elemMatch(new Criteria().exists(true)));

Jampan

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Answer 2

You can use .not

Criteria.where("arr").not().size(0)

Exaggeration