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SQL standard to escape column names?
...ody> <double quote>
Oracle, PostgreSQL, MySQL, MSSQL and SQlite all support " as the identifier delimiter.
They don't all use " as the 'default'. For example, you have to be running MySQL in ANSI mode and SQL Server only supports it when QUOTED_IDENTIFIER is ON.
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Why do I need Transaction in Hibernate for read-only operations?
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You might actually have reasons to mark transactions as read-only.
Transactions for reading might look indeed strange and often people don't mark methods for transactions in this case. But JDBC will create transaction anyway, it's just i...
How do I implement interfaces in python?
...interface, a module that is a part of the Zope Component Architecture, a really awesomely cool component framework. Here you don't subclass from the interfaces, but instead mark classes (or even instances) as implementing an interface. This can also be used to look up components from a component reg...
Select first occurring element after another element
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#many .more.selectors h4 + p { ... }
This is called the adjacent sibling selector.
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Why use Dijkstra's Algorithm if Breadth First Search (BFS) can do the same thing faster?
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Dijkstra allows assigning distances other than 1 for each step. For example, in routing the distances (or weights) could be assigned by speed, cost, preference, etc. The algorithm then gives you the shortest path from your source to e...
Why is this F# code so slow?
...es generic comparison (I thought this uses just IComparable, but it is actually more complicated - it would use structural comparison for F# types and it's fairly complex logic).
> let min3(a, b, c) = min a (min b c);;
val min3 : 'a * 'a * 'a -> 'a when 'a : comparison
In the C# version, ...
Formatting “yesterday's” date in python
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all answers are correct, but I want to mention that time delta accepts negative arguments.
>>> from datetime import date, timedelta
>>> yesterday = date.today() + timedelta(days=-1)
>>> print(y...
How to include() all PHP files from a directory?
...t because this question was about including everything in a directory - usually this would be in different directories: eg DataClass defined in BE directory and BL.class.php defined in BL directory.
– Carmageddon
May 13 '13 at 15:52
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How to get values from IGrouping
...> implements IEnumerable<TElement>, you can use SelectMany to put all the IEnumerables back into one IEnumerable all together:
List<smth> list = new List<smth>();
IEnumerable<IGrouping<int, smth>> groups = list.GroupBy(x => x.id);
IEnumerable<smth> smths = ...
Including jars in classpath on commandline (javac or apt)
trying to run this program. I think that to setup all of the web service stuff I need to run apt. (Although using javac I am having the same issue). I think what I am getting is compile errors. (Shown at bottom).
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