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How to filter SQL results in a has-many-through relation
...on easier to extend to n clubs and that avoids INTERSECT (not available in MySQL) and IN (as performance of this sucks in MySQL)
SELECT s.id,
s.name
FROM student s
join student_club sc
ON s.id = sc.student_id
WHERE sc.club_id IN ( 30, 50 )
GROUP BY s.id,
s.name
...
Scala Doubles, and Precision
...rmat way, but in locales s.a. mine (Finnish), care must be taken to fix to ROOT locale. E.g. "%.2f".formatLocal(java.util.Locale.ROOT,x).toDouble . It seems, format uses ',' because of the locale whereas toDouble is not able to take it in and throws a NumberFormatException. This of course is based o...
How to efficiently build a tree from a flat structure?
...t AssociatedObject { get; set; }
}
IEnumerable<Node> BuildTreeAndGetRoots(List<MyObject> actualObjects)
{
Dictionary<int, Node> lookup = new Dictionary<int, Node>();
actualObjects.ForEach(x => lookup.Add(x.ID, new Node { AssociatedObject = x }));
foreach (var ...
What's the easy way to auto create non existing dir in ansible
...
Right now, this is the only way
- name: Ensures {{project_root}}/conf dir exists
file: path={{project_root}}/conf state=directory
- name: Copy file
template:
src: code.conf.j2
dest: "{{project_root}}/conf/code.conf"
...
What is the difference between JSON and Object Literal Notation?
...lf. It is derived from a single language.
SQL Language - Hibernate MySQL Dialect, Oracle Dialect,.. which have some changes or added functionality.
Information about the browser and computer of your users.
navigator.appName // "Netscape"
ECMAScript is the scripting language that form...
Mac zip compress without __MACOSX folder?
...
To apply to all zip files under some root: find ~ -type f -name '*.zip' -exec zip -d '{}' __MACOSX/\* \;. Substitute your starting point for ~.
– Chris Johnson
Jun 27 '17 at 12:05
...
How to use Elasticsearch with MongoDB?
...data from everything what is supporting streams (i.e. MongoDB, PostgreSQL, MySQL, JSON files, etc)
Example for MongoDB to Elasticsearch:
Install packages:
npm install elasticbulk
npm install mongoose
npm install bluebird
Create script i.e. script.js:
const elasticbulk = require('elasticbulk')...
ListCtrl 重绘（Custom Draw） - C/C++ - 清泛网 - 专注C/C++及内核技术
...处理＂重绘过程＂中所有的脏活了。
这篇文章的焦点是如何在一个LISTCTRL控件上使用Custom Draw消息。究其原因，一部分是因为我已经在我的工作上使用了Custom Draw有一段时间了，我很熟悉它。另一个原因是这个机制确实是非常好...
IN vs OR in the SQL WHERE Clause
...')
WHERE foo = 'a' OR foo = 'b' OR foo = 'c'
According to the manual for MySQL if the values are constant IN sorts the list and then uses a binary search. I would imagine that OR evaluates them one by one in no particular order. So IN is faster in some circumstances.
The best way to know is to p...
Find all packages installed with easy_install/pip?
... print(join(package.location, package._get_metadata("top_level.txt"))) # root directory of this package
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