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How to randomly select rows in SQL?
...* FROM Table1
WHERE (ABS(CAST(
(BINARY_CHECKSUM
(keycol1, NEWID())) as int))
% 100) < 10
https://msdn.microsoft.com/en-us/library/cc441928.aspx
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What's the difference between passing by reference vs. passing by value?
...to it, I'll change the caller's variable itself, not e.g. whatever it is pointing to if it's a pointer.
This is now considered bad practice (as an implicit dependency). As such, virtually all newer languages are exclusively, or almost exclusively pass-by-value. Pass-by-reference is now chiefly use...
Calculate the number of business days between two dates?
...wer. Especially in the real world situation, when you have to examine time intervals of several months.
See my code, with comments, below.
/// <summary>
/// Calculates number of business days, taking into account:
/// - weekends (Saturdays and Sundays)
/// - bank holidays in...
What does the unary plus operator do?
...erator itself. For example, it can be used to force widening from smaller integral types to int, or ensure that an expression's result is treated as an rvalue and therefore not compatible with a non-const reference parameter. I submit, however, that these uses are better suited to code golf than r...
Is it possible to get all arguments of a function as single object inside that function?
... end])
Array.indexOf(searchElement[, fromIndex])
I think the best way to convert a arguments object to a real Array is like so:
argumentsArray = [].slice.apply(arguments);
That will make it an array;
reusable:
function ArgumentsToArray(args) {
return [].slice.apply(args);
}
(function() {...
Deleting elements from std::set while iterating
...get to the temp. For example, re-write your loop as follows:
std::set<int>::iterator it = numbers.begin();
std::set<int>::iterator tmp;
// iterate through the set and erase all even numbers ...
Cannot use ref or out parameter in lambda expressions
... can be accessed after the method frame is no longer on the stack
Func<int> Example(int p1) {
return () => p1;
}
Another property of captured variables is that changes to the variable are also visible outside the lambda expression. For example the following prints 42
void Example2(in...
Can a recursive function be inline?
...
First, the inline specification on a function is just a hint. The compiler can (and often does) completely ignore the presence or absence of an inline qualifier. With that said, a compiler can inline a recursive function, much as it can unroll an infinite loop. It simply has to ...
How to insert a SQLite record with a datetime set to 'now' in Android application?
...
so above you are taking a Date object and converting it to a string to be placed in a sqlite column.. but when you pull that string from the database, how do you convert it back to a Date object?
– erik
Apr 30 '15 at 3:34
...
Change from SQLite to PostgreSQL in a fresh Rails project
...in SQLite (The dev and production). Since I am moving to heroku, I want to convert my database to PostgreSQL.
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