大约有 40,000 项符合查询结果（耗时：0.0913秒） [XML]
Nullable Foreign Key bad practice?
... read.
Only if you know better than Chris Date "what first normal form really means". If x and y are both nullable, and indeed in some row x and y are both null, then WHERE x=y does not yield true. This proves beyond reasonable doubt that null is not a value (because any real value is always equ...
Why are regular expressions so controversial? [closed]
...ions. And not just slow, but the performance of the regex engine can be totally unpredictable when faced with arbitrary (user-supplied) inputs.
– Pacerier
Dec 1 '15 at 21:53
...
Can functions be passed as parameters?
... result = quote123(foo)
fmt.Println(result)
// Output: "foo"
_ = convert(foo) // confirm foo satisfies convert at runtime
// fails due to argument type
// _ = convert(func(x float64) string { return "" })
}
Play: http://play.golang.org/p/XNMtrDUDS0
Tour: https://tour.golang...
Installed Java 7 on Mac OS X but Terminal is still using version 6
...ere isn't really a need for it anymore. Instead you have to use export JAVA_HOME=`/usr/libexec/java_home -v 1.7` to switch to the latest Java 7 JDK from Oracle.
– Uwe Günther
Mar 9 '13 at 2:54
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How to allow http content within an iframe on a https site
...e server online. Do the following steps:
Prepare your proxy server - install IIS, Apache
Get valid SSL certificate to avoid security errors (free from startssl.com for example)
Write a wrapper, which will download insecure content (how to below)
From your site/app get https://yourproxy.com/?page=h...
How do you mock out the file system in C# for unit testing?
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Edit: Install the NuGet package System.IO.Abstractions.
This package did not exist when this answer was originally accepted. The original answer is provided for historical context below:
You could do it by creating an interface:
inter...
Code equivalent to the 'let' keyword in chained LINQ extension method calls
...ime it's executed:
var seq = EnumerableEx.Generate(
new Random(),
_ => true,
_ => _,
x => x.Next());
To see that new random samples show up every time, consider the following
seq.Zip(seq, Tuple.Create).Take(3).Dump();
which produces pairs in which the left and right ar...
Are PHP functions case sensitive?
I was digging through some code, and I found some calls to mySQL_fetch_array . Is PHP case sensitive about function names? I recall reading this somewhere but can't seem to find any reference to it.
...
Jackson and generic type reference
...erasure: T is just a type variable, and you must indicate actual class, usually as Class argument. Without such information, best that can be done is to use bounds; and plain T is roughly same as 'T extends Object'. And Jackson will then bind JSON Objects as Maps.
In this case, tester method needs ...
Initialise a list to a specific length in Python [duplicate]
...dicts, do not use [{}]*10 -- that would give you a list with the same initially-empty dict ten times, not ten distinct ones. Rather, use [{} for i in range(10)] or similar constructs, to construct ten separate dicts to make up your list.
...