java API to retrieve max, min and unique values in MongoDB

[Shi Yu]

Hi,

What is the simplest Java API to retrieve the max, min and unique values in MongoDB collections? I was looking for something like the SQL "SELECT max( ) FROM" for the Servlet but didn't get any. It sounds as a very straightforward requirement and it should be done in a single line command. I did found some hints in the cookbook using Map/Reduce, but that seems requiring some coding, isn't it? Anyone has a quick example fining max, min and unique values using Map/Reduce (Java API at the servlet side)? Thanks.

Shi

[Nat]

- for min, max, use sort and limit i.e.
sort({ score : 1}).limit(1) // for min
sort({ score : -1}).limit(1) // for max

- for unique value, use distinct or group (http://www.mongodb.org/
display/DOCS/Aggregation)

[Shi Yu]

Ah! Thank you Nat!

Shi

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[CodeBeast]

Isn't it
sort({ score : 1}).limit(1) // for max
sort({ score : -1}).limit(1) // for min
???