大约有 30,000 项符合查询结果（耗时：0.0380秒） [XML]
SQL Server: Difference between PARTITION BY and GROUP BY
...on and the MAX amount across all sales regions in the same row.
This does mean you will have repeating data, but it may suit the end consumer in the sense that data has been aggregated but no data has been lost - as would be the case with GROUP BY.
...
How to tell if browser/tab is active [duplicate]
...ment.hidden) {
// do what you need
}
This specification defines a means for site developers to
programmatically determine the current visibility state of the page in
order to develop power and CPU efficient web applications.
Learn more (2019 update)
All modern browsers are supportin...
To ARC or not to ARC? What are the pros and cons? [closed]
...ing to say, but there you go. ARC might retain some things that you didn't mean it to retain, but it'll release them as well, so it'll never matter. If I were teaching a new class in Cocoa today, I'd probably spend no more than five minutes on the actual memory management rules, and I'd probably onl...
View's SELECT contains a subquery in the FROM clause
...SQL 5.7.7, subqueries cannot be used in the FROM clause of a view.
This means, that choosing a MySQL v5.7.7 or newer or upgrading the existing MySQL instance to such a version, would remove this restriction on views completely.
However, if you have a current production MySQL version that is earl...
Why is Spring's ApplicationContext.getBean considered bad?
...nnotations improve things but there is still a lot of XML out there). That means developers can't work on your program unless they know all the magic tags defined by Spring. It is not good enough to know Java anymore. This hinders less experience programmers (ie. it is actually poor design to use a ...
What does the tilde before a function name mean in C#?
... true of destructors are true of finalizers, and vice versa, but the words mean slightly different things.
– supercat
Jan 16 '14 at 18:05
add a comment
|
...
What does “1 line adds whitespace errors” mean when applying a patch?
... command outputs warning messages but applies the patch.
So, the "error" means that the change introduces a trailing whitespace, a whitespace-only line, or a space that precedes a tab. Other than that fact, there is nothing erroneous about the change, and it will apply cleanly and correctly. In ot...
Elements order in a “for (… in …)” loop
...ction stored in a property of an object is called a method.
I guess that means you cant rely on the properties being enumerated in a consistent order across JavaScript implementations. (It would be bad style anyway to rely on implementation-specific details of a language.)
If you want your order ...
Why do I need to override the equals and hashCode methods in Java?
... @VikasVerma equals object will have equal hashcode doesn't mean unequal object will have unequal hashcode. What if objects are actually different, but their hashcode is same ?
– Ravi
Dec 12 '17 at 6:21
...
Is there a float input type in HTML5?
...Code <= 57) ||
event.charCode == 46 || event.charCode == 0 ">
Meaning :
Char code :
48-57 equal to 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
0 is Backspace(otherwise need refresh page on Firefox)
46 is dot
&& is AND , || is OR operator.
if you try float with comma :
<input type="te...