What's the best way to do a query like this in MongoDB?
SELECT * FROM things WHERE (a = 1 or b = 1) and (c = 2 or d = 2)
Thanks.
views:
54answers:
2
+1
A:
You can use the $or expression.
db.things.find( { $or : [ { a : 1}, { b : 1 } ], $or : [ { c : 2 }, { d : 2 } ] } )
halfdan
2010-10-02 23:13:19
Right idea but clearly the wrong answer. Test case: db.things.save({"b" : 1, "c" : 2}); db.things.find( { $or : [ { a : 1, b : 1 } , { c : 2, d : 2 } ] } ); Satisfies both halves of the and clause from above, but does not come back with your query.
Gates VP
2010-10-03 06:09:29
@Gates VP: You're right indeed. Thanks for noticing, I've updated my answer.
halfdan
2010-10-03 08:39:40
+1
A:
@Drew, the correct answer for this query is the following:
db.test.find( { $or : [ { a : 1}, { b : 1 } ], $or : [ { c : 2 }, { d : 2 } ] } )
That's a = 1 or b = 1 and c = 2 or d = 2. If you look at the code, you'll notice that you have two or clauses separated by a comma. When doing a find, the comma is effectively the and clause.
For docs on using the $or clause, see here.
Gates VP
2010-10-03 06:06:29
Thanks, now I wonder how I use that with a the node-mongodb-native library. It is not a valid javascript object because it has two keys of the same name.
Drew LeSueur
2010-10-04 17:48:28
OK, NodeJS and NodeMongo are really new. We're talking about a first commit on July 4th. Honestly I would just go to the github page and message the developers directly: http://github.com/christkv/node-mongodb-native
Gates VP
2010-10-05 14:48:27