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NULL values inside NOT IN clause
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@binki, You query executes if run here rextester.com/l/sql_server_online_compiler but does not work if run here sqlcourse.com/cgi-bin/interpreter.cgi.
– Istiaque Ahmed
Nov 10 '17 at 13:57
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Android 4.3 Bluetooth Low Energy unstable
...am currently developing an application that will use Bluetooth Low Energy (testing on the Nexus 4). After getting started with the official BLE APIs in Android 4.3, I have noticed that after I connect a device for the first time I am rarely able to successfully connect to / communicate with that dev...
Error: «Could not load type MvcApplication»
...evious version of the project which had a different name. So the namespace Test should have been namespace Test.WebUI. A silly mistake of course and am a bit embarrassed to write this! But writing in the hope that a similar error from anyone else may lead him to check this trivial aspect as well.
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How to check if a variable is not null?
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Here is how you can test if a variable is not NULL:
if (myVar !== null) {...}
the block will be executed if myVar is not null.. it will be executed if myVar is undefined or false or 0 or NaN or anything else..
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Skip List vs. Binary Search Tree
... locked.
Update from Jon Harrops comments
I read Fraser and Harris's latest paper Concurrent programming without locks. Really good stuff if you're interested in lock-free data structures. The paper focuses on Transactional Memory and a theoretical operation multiword-compare-and-swap MCAS. B...
change cursor to finger pointer
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After testing this, it seems like it's necessary to have both onmouseover="" AND style=cursor: pointer;". If you just have the style tag, the pointer pointer cursor will disappear/default to the standard pointer after one click int...
How do I run Asynchronous callbacks in Playground
...ate: NSDate())
usleep(10)
}
This pattern has often been used in Unit Tests which need to test async callbacks, for example: Pattern for unit testing async queue that calls main queue on completion
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HashSet vs LinkedHashSet
...the most of the time we use Set structures for iterating.
Performance tests:
------------- TreeSet -------------
size add contains iterate
10 746 173 89
100 501 264 68
1000 714 410 69
10000 1975 552 69
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Best way to store date/time in mongodb
...JavaScript Date objects, which map onto BSON native Date objects.
> db.test.insert({date: ISODate()})
> db.test.insert({date: new Date()})
> db.test.find()
{ "_id" : ObjectId("..."), "date" : ISODate("2014-02-10T10:50:42.389Z") }
{ "_id" : ObjectId("..."), "date" : ISODate("2014-02-10T10:5...
How can I check for “undefined” in JavaScript? [duplicate]
What is the most appropriate way to test if a variable is undefined in JavaScript?
16 Answers
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