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How to get primary key column in Oracle?
...e which is called test and then query
create table test
(
id int,
name varchar2(20),
city varchar2(20),
phone int,
constraint pk_id_name_city primary key (id,name,city)
);
SELECT cols.table_name, cols.column_name, cols.position, cons.status, cons.owner FROM all_constraints cons, all_cons_columns c...
svn: replace trunk with branch
...ations/reorganizations using svndumpfilter. There are times when a little extra work now can save a lot of extra work later, and by keeping an easy use of svndumpfilter available for future migrations/reorganizations mitigates the risk at a relatively low cost.
...
What's the difference between Task.Start/Wait and Async/Await?
...he calling thread will not block and continue executing.
static void Main(string[] args)
{
WriteOutput("Program Begin");
// DoAsTask();
DoAsAsync();
WriteOutput("Program End");
Console.ReadLine();
}
static void DoAsTask()
{
WriteOutput("1 - Starting");
var t = Task.Fact...
Reference requirements.txt for the install_requires kwarg in setuptools setup.py file
...
It can't take a file handle. The install_requires argument can only be a string or a list of strings.
You can, of course, read your file in the setup script and pass it as a list of strings to install_requires.
import os
from setuptools import setup
with open('requirements.txt') as f:
requi...
Handling the window closing event with WPF / MVVM Light Toolkit
...cept complexity by using a more elaborate pattern with more indirection (5 extra lines of XAML plus Command pattern).
The "zero code-behind" mantra is not the goal in itself, the point is to decouple ViewModel from the View. Even when the event is bound in code-behind of the View, the ViewModel do...
How to check if an object is nullable?
...t;T>(T? t) where T : struct { return true; }
}
then
static void Main(string[] args)
{
int a = 123;
int? b = null;
object c = new object();
object d = null;
int? e = 456;
var f = (int?)789;
bool result1 = ValueTypeHelper.IsNullable(a); // false
bool result2 = Val...
How do I toggle an element's class in pure JavaScript?
...e seperators. for example it doesn't work if class name contain dash ("-") char: btn, btn-red will both match'\\b' + 'btn' + '\\b' !!
– S.Serpooshan
Feb 5 '19 at 6:47
...
Designing function f(f(n)) == -n
...oof of why such a function can't exist, for all numbers, if it doesn't use extra information(except 32bits of int):
We must have f(0) = 0. (Proof: Suppose f(0) = x. Then f(x) = f(f(0)) = -0 = 0. Now, -x = f(f(x)) = f(0) = x, which means that x = 0.)
Further, for any x and y, suppose f(x) = y. We w...
RabbitMQ and relationship between channel and connection
...nections.
You can use one Channel for everything. However, if you have multiple threads, it's suggested to use a different Channel for each thread.
Channel thread-safety in Java Client API Guide:
Channel instances are safe for use by multiple threads. Requests into
a Channel are serialized, ...
Convert seconds to Hour:Minute:Second
...2:22:05
See: SEC_TO_TIME
Run the Demo
PostgreSQL example:
SELECT TO_CHAR('8525 second'::interval, 'HH24:MI:SS');
# 02:22:05
Run the Demo
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