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javax.faces.application.ViewExpiredException: View could not be restored
... application with container-managed security. The problem is when I log in and open another page on which I logout, then I come back to first page and I click on any link etc or refresh page I get this exception. I guess it's normal (or maybe not:)) because I logged out and session is destroyed. Wha...
What are the rules about using an underscore in a C++ identifier?
...e allowed to add template specializations, though.)
From the 2003 C++ Standard:
17.4.3.1.2 Global names [lib.global.names]
Certain sets of names and function signatures are always reserved to the implementation:
Each name that contains a double underscore (__) or begins with an u...
How do I check if a column is empty or null in MySQL?
...e_col = ' ' (one space inserted in the string) then it works on both MySQL and Oracle, see answer of "onedaywhen". some_col = '' doesn't work on Oracle as empty strings mean NULL there.
– Johanna
May 18 '15 at 14:07
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Understanding REST: Verbs, error codes, and authentication
... APIs around default functions in my PHP-based web applications, databases and CMSs.
10 Answers
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ETag vs Header Expires
...d around but haven't been able to figure out if I should use both an ETag and an Expires Header or one or the other.
8 ...
What is the difference between Left, Right, Outer and Inner Joins?
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Simple Example: Lets say you have a Students table, and a Lockers table. In SQL, the first table you specify in a join, Students, is the LEFT table, and the second one, Lockers, is the RIGHT table.
Each student can be assigned to a locker, so there is a LockerNumber column in...
Any good boolean expression simplifiers out there? [closed]
I was refactoring old code and encountered several IF conditions that were way too complex and long and I'm certain they can be simplified. My guess is that those conditions grew so much because of later modifications.
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Algorithm for Determining Tic Tac Toe Game Over
I've written a game of tic-tac-toe in Java, and my current method of determining the end of the game accounts for the following possible scenarios for the game being over:
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Is it safe to check floating point values for equality to 0?
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It is safe to expect that the comparison will return true if and only if the double variable has a value of exactly 0.0 (which in your original code snippet is, of course, the case). This is consistent with the semantics of the == operator. a == b means "a is equal to b".
It is not sa...
What does ||= (or-equals) mean in Ruby?
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This question has been discussed so often on the Ruby mailing-lists and Ruby blogs that there are now even threads on the Ruby mailing-list whose only purpose is to collect links to all the other threads on the Ruby mailing-list that discuss this issue.
Here's one: The definitive list of ||= ...