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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...
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
...
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...
How do you mock out the file system in C# for unit testing?
...
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...
select、poll、epoll之间的区别总结[整理] - C/C++ - 清泛网 - 专注C/C++及内核技术
...1、select实现
select的调用过程如下所示：
（1）使用copy_from_user从用户空间拷贝fd_set到内核空间
（2）注册回调函数__pollwait
（3）遍历所有fd，调用其对应的poll方法（对于socket，这个poll方法是sock_poll，sock_poll根据情况会调用到...
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.
...
Spring .properties file: get element as an Array
... this is what I want, but in env vars... I should be able to use SOME_KEY_0_=yes SOME_KEY_1=no, etc in env vars, but my getProperty is coming back null
– Rhubarb
Apr 30 at 20:56
...
Regular Expression For Duplicate Words
...)\s+\b\1\b/
A good selection of test strings can be found here: http://callumacrae.github.com/regex-tuesday/challenge1.html
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