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How to create a MySQL hierarchical recursive query
... parent_id
from products
where parent_id = 19
union all
select p.id,
p.name,
p.parent_id
from products p
inner join cte
on p.parent_id = cte.id
)
select * from cte;
The value specified in parent_id = 19 should be set to the...
Java equivalent to #region in C#
...
Actually this can be achieved. If you scroll down on this post "Yaqub Ahmad" explains how to get this functionality. Also here is a link (kosiara87.blogspot.com/2011/12/…) that shows you how to add it to your existing eclipse e...
Detect if device is iOS
... are changed and differentiating between iPad and MacOS seems possible, so all answers below needs to take that into account now.
This might be the shortest alternative that also covers iOS 13:
function iOS() {
return [
'iPad Simulator',
'iPhone Simulator',
'iPod Simulator',
'iPad'...
Extract elements of list at odd positions
...
Solution
Yes, you can:
l = L[1::2]
And this is all. The result will contain the elements placed on the following positions (0-based, so first element is at position 0, second at 1 etc.):
1, 3, 5
so the result (actual numbers) will be:
2, 4, 6
Explanation
The [1::2]...
Sleep for milliseconds
... facilities:
#include <chrono>
#include <thread>
std::this_thread::sleep_for(std::chrono::milliseconds(x));
Clear and readable, no more need to guess at what units the sleep() function takes.
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CoffeeScript, When to use fat arrow (=>) over arrow (->) and vice versa
When building a class in CoffeeScript, should all the instance method be defined using the => ("fat arrow") operator and all the static methods being defined using the -> operator?
...
What is an xs:NCName type and when should it be used?
...s, then they are NCNames.
xs:string puts no restrictions on your names at all, but xs:NCName basically disallows ":" to appear in the string.
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lua和c/c++互相调用实例分析 - C/C++ - 清泛网 - 专注C/C++及内核技术
...lua的运行环境，相关接口如下：
//创建lua运行上下文
lua_State* luaL_newstate(void) ;
//加载lua脚本文件
int luaL_loadfile(lua_State *L, const char *filename);
lua和c/c++的数据交互通过"栈"进行 ,操作数据时，首先将数据拷贝到"栈"上，然后获取...
How to access component methods from “outside” in ReactJS?
...
class Parent extends React.Class {
constructor(props) {
this._child = React.createRef();
}
componentDidMount() {
console.log(this._child.current.someMethod()); // Prints 'bar'
}
render() {
return (
<div>
<Child ref=...
design a stack such that getMinimum( ) should be O(1)
...
EDIT: This fails the "constant space" constraint - it basically doubles the space required. I very much doubt that there's a solution which doesn't do that though, without wrecking the runtime complexity somewhere (e.g. making push/pop O(n)). Note that this doesn't change the complex...