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Why are Where and Select outperforming just Select?
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+1 for being the only answer (so far) that actually addresses the question, doesn't guess the answer and doesn't just generate "me too!" statistics.
– Binary Worrier
Aug 20 '13 at 13:21
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Method Overloading for null argument
...thod that's available (see JLS §15.12.2).
Object, char[] and Integer can all take null as a valid value. Therefore all 3 version are applicable, so Java will have to find the most specific one.
Since Object is the super-type of char[], the array version is more specific than the Object-version. S...
Why do I need 'b' to encode a string with Base64?
...-z, 0-9, +, /* so it can be transmitted over channels that do not preserve all 8-bits of data, such as email.
Hence, it wants a string of 8-bit bytes. You create those in Python 3 with the b'' syntax.
If you remove the b, it becomes a string. A string is a sequence of Unicode characters. base64 ha...
Rails 3: Get Random Record
...; rand(Thing.count))
# Rails 3
Thing.offset(rand(Thing.count)).first
Actually, in Rails 3 all examples will work. But using order RANDOM is quite slow for big tables but more sql-style
UPD. You can use the following trick on an indexed column (PostgreSQL syntax):
select *
from my_table
where i...
What's the best way to store a group of constants that my program uses? [closed]
...way to store them? I don't think I want an Enum , because the data is not all the same type, and I want to manually set each value. Should I just store them all in an empty class? Or is there a better way?
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How do I move an issue on github to another repo?
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Would be great to be able to move all issues of one repo to another.
– CGFoX
Jun 23 '19 at 17:43
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How to request a random row in SQL?
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-1 for relying on order by rand() or equivalents in all dbs :|. also mentioned here.
– AD7six
May 26 '14 at 9:27
21
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What is The Rule of Three?
...in various contexts,
and we should understand what "copying an object" actually means.
Let us consider a simple example:
class person
{
std::string name;
int age;
public:
person(const std::string& name, int age) : name(name), age(age)
{
}
};
int main()
{
person a("Bjar...
Notepad++ Multi editing
...d select the lines you want. Then type. The text you type is inserted on all of the lines you selected.
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HashMap and int as key
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You can't use a primitive because HashMap use object internally for the key. So you can only use an object that inherits from Object (that is any object).
That is the function put() in HashMap and as you can see it uses Object for K:
public V put(K key, V value) {
if (key == nu...