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Does order of where clauses matter in SQL?
...
The order of WHERE clauses should not make a difference in a database that conforms to the SQL standard. The order of evaluation is not guaranteed in most databases.
Do not think that SQL cares about the order. The following generates an error in SQL Server:
select *
from INFORMATION_S...
How to compare type of an object in Python?
...
isinstance works:
if isinstance(obj, MyClass): do_foo(obj)
but, keep in mind: if it looks like a duck, and if it sounds like a duck, it is a duck.
EDIT: For the None type, you can simply do:
if obj is None: obj = MyClass()
...
Scala: List[Future] to Future[List] disregarding failed futures
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def futureToFutureTry[T](f: Future[T]): Future[Try[T]] =
f.map(Success(_)).recover { case x => Failure(x)}
val listOfFutures = ...
val listOfFutureTrys = listOfFutures.map(futureToFutureTry(_))
Then use Future.sequence as before, to give you a Future[List[Try[T]]]
val futureListOfTrys = F...
Javascript regex returning true.. then false.. then true.. etc [duplicate]
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/^[^-_]([a-z0-9-_]{4,20})[^-_]$/gi;
You're using a g (global) RegExp. In JavaScript, global regexen have state: you call them (with exec, test etc.) the first time, you get the first match in a given string. Call them again and ...
Get name of object or class
... use standard IIFE (for example with TypeScript)
var Zamboch;
(function (_Zamboch) {
(function (Web) {
(function (Common) {
var App = (function () {
function App() {
}
App.prototype.hello = function () {
co...
How to print a dictionary line by line in Python?
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I do print(json.dumps(cars, indent=4, ensure_ascii=False)) because otherwise non-ASCII characters are unreadable.
– Boris
Apr 22 at 16:36
add a ...
How do I create a copy of an object in PHP?
...an be seen from this example: $a = new stdClass; $b =& $a; $a = 42; var_export($b); here $b is a reference to the variable $a; if you replace =& with a normal =, it is not a reference, and still points to the original object.
– IMSoP
Jun 16 '13 at 21:14...
Managing constructors with many parameters in Java
...er the following example
public class StudentBuilder
{
private String _name;
private int _age = 14; // this has a default
private String _motto = ""; // most students don't have one
public StudentBuilder() { }
public Student buildStudent()
{
return new Student...
How to write inline if statement for print?
... condition:
block
if expression (introduced in Python 2.5)
expression_if_true if condition else expression_if_false
And note, that both print a and b = a are statements. Only the a part is an expression. So if you write
print a if b else 0
it means
print (a if b else 0)
and similarly ...
实战低成本服务器搭建千万级数据采集系统 - 更多技术 - 清泛网 - 专注C/C++...
...器。到了机器后再按照天或者半天分表，比如表名为 weibo_2013020101 、weibo_2013020112。weibo_2013020101表示2月1日上午一个表，weibo_2013020112表示2月1日下午一个表。光这样分了还是不够，1000w/2=500w，经不起压力扩展。我们还需要把表再...