Query distinct not null values in MongoDb

Ask Time：2013-04-22T19:22:43 Author：hfogel

I'm just beginning to learn MongoDb and am having some problems with distinct queries.

If I for instance run the query

db.images.distinct('gallery')

I get the expected result, but also empty strings and null values. How can I write a query that just returns the values that are not null?

Thanks

Author:hfogel，eproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/16145962/query-distinct-not-null-values-in-mongodb

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