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E11000 duplicate key error index in mongodb mongoose
... null value.
In other words, a sparse index is ok with multiple documents all having null values.
sparse indexes
From comments:
Your error says that the key is named mydb.users.$email_1 which makes me suspect that you have an index on both users.email and users.local.email (The former being old an...
Remove Object from Array using JavaScript
...
This however will remove all the occurrences found, not only the first one
– Flavien Volken
Jul 12 '16 at 6:49
6
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Regular cast vs. static_cast vs. dynamic_cast [duplicate]
... twenty years, but there's one aspect of these languages that I've never really understood. I've obviously used regular casts i.e.
...
How do you create a Swift Date object?
... dateFromString. If you wanted to return a nil on bad parses, you would ideally use a failible initializer; but you cannot do that now (June 2015), because of a limitation in Swift 1.2, so then you're next best choice is to use a class factory method.
A more elaborate example, which addresses both ...
How to write a Unit Test?
...input.
Now, implement the test by declaring a class, name it anything (Usually something like TestAddingModule), and add the testAdd method to it (i.e. like the one below) :
Write a method, and above it add the @Test annotation.
In the method, run your binary sum and assertEquals(expectedVal,cal...
How to customize a Spinner in Android
...er"
android:src="@mipmap/drop" />
</RelativeLayout>
Finally looks like below image and it is everywhere clickable in round area and no need to write click Lister for imageView.
Step3: For drop-down design, remove the line from Dropdown ListView and change the background color,...
Debugging Scala code with simple-build-tool (sbt) and IntelliJ
... running the remote JVM -- something like
-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=5005
Launch sbt with these arguments and then execute jetty-run. Finally, launch your remote debug configuration in IntelliJ. This thread might be useful.
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How to set HTTP headers (for cache-control)?
...low.
Some information on the Cache-Control header is as follows
HTTP 1.1. Allowed values = PUBLIC | PRIVATE | NO-CACHE | NO-STORE.
Public - may be cached in public shared caches.
Private - may only be cached in private cache.
No-Cache - may not be cached.
No-Store - may be cached but not archived.
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How to get year, month, day, hours, minutes, seconds and milliseconds of the current moment in Java?
...t an int to String, make use of String#valueOf().
If your intent is after all to arrange and display them in a human friendly string format, then better use either Java8's java.time.format.DateTimeFormatter (tutorial here),
LocalDateTime now = LocalDateTime.now();
String format1 = now.format(DateTi...
Catch Ctrl-C in C
...ote this answer seven years ago. Yes, language standards change. If you really must better the world, please add your new answer but leave mine as is. As the answer has my name on it, I'd prefer it to contain my words too. Thank you.
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