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Should MySQL have its timezone set to UTC?
...ion` tzt
INNER JOIN mysql.`time_zone_transition_type` tztt USING(Time_zone_id, Transition_type_id)
INNER JOIN mysql.`time_zone_name` tzn USING(Time_zone_id)
-- WHERE tzn.Name LIKE 'Europe/Moscow' -- Moscow has weird DST changes
ORDER BY tzt.Transition_time ASC
CONVERT_TZ also applies any necessary...
Why should I declare a virtual destructor for an abstract class in C++?
.... When they come to delete it, if the destructor is non-virtual, they will call the interface's destructor (or the compiler-provided default, if you didn't specify one), not the derived class's destructor. Instant memory leak.
For example
class Interface
{
virtual void doSomething() = 0;
};
cl...
What does principal end of an association means in 1:1 relationship in Entity framework
...use:
public class Boo
{
[Key, ForeignKey("Foo")]
public string BooId{get;set;}
public Foo Foo{get;set;}
}
Or fluent mapping
modelBuilder.Entity<Foo>()
.HasOptional(f => f.Boo)
.WithRequired(s => s.Foo);
...
JavaScript curry: what are the practical applications?
...tself—is useful in JavaScript; it is a technique for converting function calls with multiple arguments into chains of function calls with a single argument for each call, but JavaScript supports multiple arguments in a single function call.
In JavaScript—and I assume most other actual language...
how to replicate pinterest.com's absolute div stacking layout [closed]
... would like the results sorted left to right. Any direction you could provide to make it myself would be greatly appreciated.
...
SQLiteDatabase.query method
... null, null, orderBy);
// since we have a named column we can do
int idx = c.getColumnIndex("max");
is equivalent to the following raw query
String queryString =
"SELECT column1, (SELECT max(column1) FROM table1) AS max FROM table1 " +
"WHERE column1 = ? OR column1 = ? ORDER BY colu...
cartesian product in pandas
...e cartesian product on.
My use case was that I needed a list of all store IDs on for each week in my list. So, I created a list of all the weeks I wanted to have, then a list of all the store IDs I wanted to map them against.
The merge I chose left, but would be semantically the same as inner in t...
When is SQLiteOpenHelper onCreate() / onUpgrade() run?
...
SQLiteOpenHelper onCreate() and onUpgrade() callbacks are invoked when the database is actually opened, for example by a call to getWritableDatabase(). The database is not opened when the database helper object itself is created.
SQLiteOpenHelper versions the database...
What is the difference between a static and a non-static initialization code block
...java class, and run only one time before the constructor or main method is called.
OK! Tell me more...
is a block of code static { ... } inside any java class. and executed by virtual machine when class is called.
No return statements are supported.
No arguments are supported.
No this or super ar...
Strangest language feature
...
In JavaScript, the following construct
return
{
id : 1234,
title : 'Tony the Pony'
};
returns undefined is a syntax error due to the sneaky implicit semicolon insertion on the newline after return. The following works as you would expect though:
return {
id : 12...