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must appear in the GROUP BY clause or be used in an aggregate function
... this issue, you must calculate the aggregate in a sub-query and then join it with itself to get the additional columns you'd need to show:
SELECT m.cname, m.wmname, t.mx
FROM (
SELECT cname, MAX(avg) AS mx
FROM makerar
GROUP BY cname
) t JOIN makerar m ON m.cname = t.cname AND t.mx...
Is floating point math broken?
...
Binary floating point math is like this. In most programming languages, it is based on the IEEE 754 standard. The crux of the problem is that numbers are represented in this format as a whole number times a power of two; rational numbers (such as 0.1, which is 1/10) whose denominator is not a pow...
Javascript when to use prototypes
I'd like to understand when it is appropriate to use prototype methods in js. Should they always be used? Or are there cases where using them is not preferred and/or incurs a performance penalty?
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What does the “map” method do in Ruby?
... |n| n * n } #=> [1, 4, 9]
Array and Range are enumerable types. map with a block returns an Array. map! mutates the original array.
Where is this helpful, and what is the difference between map! and each? Here is an example:
names = ['danil', 'edmund']
# here we map one array to another, c...
Would you, at present date, use JBoss or Glassfish (or another) as Java EE server for a new project?
... do need them, then that removes several of your options including my favorite, Jetty.
Do you have to use any of the other major J2EE technologies like JMS, ESB, etc? If so, and you really can't do without, then you are again constrained to a full-blown J2EE container. Carefully think and investi...
data.table vs dplyr: can one do something well the other can't or does poorly?
I'm relatively familiar with data.table , not so much with dplyr . I've read through some dplyr vignettes and examples that have popped up on SO, and so far my conclusions are that:
...
How to disable anchor “jump” when loading a page?
...sh) {
setTimeout(function() {
window.scrollTo(0, 0);
}, 1);
}
Edit: tested and works in Firefox, IE & Chrome on Windows.
Edit 2: move setTimeout() inside if block, props @vsync.
share
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Why does auto a=1; compile in C?
...ause local scope is the default for a variable declared inside a function, it's also the same as int a in this example.
This keyword is actually a leftover from C's predecessor B, where there were no base types: everything was int, pointer to int, array of int.(*) Declarations would be either auto ...
Java: when to use static methods
I am wondering when to use static methods? Say if I have a class with a few getters and setters, a method or two, and I want those methods only to be invokable on an instance object of the class. Does this mean I should use a static method?
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What's the best way to communicate between view controllers?
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These are good questions, and its great to see that you're doing this research and seem concerned with learning how to "do it right" instead of just hacking it together.
First, I agree with the previous answers which focus on the importance of putting da...