I have collection as follows .
{
"name" : "pqr" ,
"loc" :
[
{"area" : "c" , "country" : "d"},
{"area" : "w" , "country" : "r"}
]
}
I want to make which match such that only match the first element of array loc
that means if
- gives area as c or country d then it return document.
- gives area as w or country as r the开发者_如何学Pythonn does not return element
only match first element of mongo array
Is this possible in mongo ?
if some one knows plz reply
Thanks
So if you want return only first matched element you should use limit(n)
and queries like this:
1.gives area as c or country d then it return document.
db.items.find( { $or : [ {"loc.area": "c" } ,
{"loc.country ": "d" } ] } ).limit(1);
2.gives area as w or country as r then does not return element
db.items.find( { $or : [ {"loc.area": { "$ne" : "w" } },
{"loc.country": { "$ne" : "r" } } ] } ).limit(1);
If you want to search only in the first elements of nested array you can do it using positional operator by adding .0.
-> loc.0.area
.
Update: I've misunderstand your question first. Now i see that you looking for loc.0.area.
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