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How to query by datetime in Doctrine MongoDB ODM?

Is it possible to use a SQL style 'union' and 'pseudo column' in a MongoDB query?

  • Can the following sql query be done as a mongo query?  (this would solve a big problem for me) select * from ( select attribute1, '100' from collection where attribute2 = 1 union select attribute1, '200' from collection where attribute2 = 2 )  where rownum between 1 and 20    order by attribute1

  • Answer:

    Something like this? db.collection.find({$or: [ {attribute2: 1}, {attribute2: 2}]}).sort({attribute1:1}).limit(20)

Harry Heymann at Quora Visit the source

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So MongoDB doesn't have the "pseudo column" in the query language. However, I'm not clear that your query actually requires either the "pseudo column" or the "union". The "pseudo column" is just a function of attribute2 and the union is basically an "OR" clause. Did you mean "order by pseudo column"?

Gaëtan Voyer-Perrault

Take a look at the Aggregation framework in 2.1.0 and above. http://www.mongodb.org/display/DOCS/Aggregation+Framework This would allow for the projection of the '100' and '200' values during the processing.

Alvin Richards

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