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How do you query for “is not null” in Mongo?
...s:
db.test.insert({"num":1, "check":"check value"});
db.test.insert({"num":2, "check":null});
db.test.insert({"num":3});
This will return all three documents:
db.test.find();
This will return the first and second documents only:
db.test.find({"check":{$exists:true}});
This will return the first d...
Reading a List from properties file and load with spring annotation @Value
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Ahmed Ashour
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answered Sep 25 '12 at 9:41
Wilhelm KleuWilhelm Kleu
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Simpler way to create dictionary of separate variables?
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Co-variant array conversion from x to y may cause run-time exception
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edited Feb 4 '15 at 16:27
answered Jan 2 '12 at 19:02
An...
Proper MIME type for OTF fonts
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answered May 25 '10 at 18:28
spdspd
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How do I repeat an edit on multiple lines in Vim?
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:10,20s/^/,/
Or use a macro, record with:
q a i , ESC j h q
use with:
@ a
Explanation: q a starts recording a macro to register a, q ends recording. There are registers a to z available for this.
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Unable to load config info from /usr/local/ssl/openssl.cnf on Windows
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edited Oct 29 '18 at 15:01
mikemaccana
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How do I get the number of elements in a list?
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2690
The len() function can be used with several different types in Python - both built-in types a...
std::cin input with spaces?
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answered Apr 30 '11 at 0:52
PetePete
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