Allow for equality queries with respect to arrays or primitives [DATAMONGO-1897]

[spring-projects-issues]

Rafal Glowinski opened DATAMONGO-1897 and commented

Having a simple MongoDB document that contains an array:

{ 
    "type": "SOME_TYPE",
    "permissions" : ["A", "B", "C"]
}

I would like to find all documents that match this MongoDB query:

{ "type": "SOME_TYPE", "permissions": { $elemMatch: { $eq: "B" } } }

Currently, I have to use this construct:

Criteria.where("type").is("SOME_TYPE").and("permissions").elemMatch(new Criteria().in("B"))

which translates to:

{ "type": "SOME_TYPE", "permissions": { $in: ["B"] } }

What is missing, in my opinion, is a method 'eq' on Criteria, that would let us write:

Criteria.where("type").is("SOME_TYPE").and("permissions").elemMatch(new Criteria().eq("B"))

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Attachments:

• DATAMONGO-1897.patch (3.02 kB)

[spring-projects-issues]

Rafal Glowinski commented

Unless I am terribly oversimplifying the issue... this patch should contain most of the changes required to implement this functionality...

[spring-projects-issues]

Mark Deazley commented

+Side Issue: Documentation should MAKE IT VERY CLEAR what Criteria method generates an "$eq: operator:+

I want a little crazy trying to find out what generated a $eq criteria: The documentation at 10.6.1. Querying Documents in a Collection never mentions the "$eq" operator.

Maybe the people who wrote the code understand what Criteria method s/b used, I had to experiment to find out I wanted Criteria:is().

And please document the Criteria:equals() .re. is it a method that generates MongoDB operators .or. not?