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How can I define a composite primary key in SQL?
...for the table and neither value can be NULL. If you do a query like this:
SELECT * FROM voting WHERE QuestionID = 7
it will use the primary key's index. If however you do this:
SELECT * FROM voting WHERE MemberID = 7
it won't because to use a composite index requires using all the keys from th...
Installing Apple's Network Link Conditioner Tool
...per.apple.com/download/more/?q=Additional%20Tools
Install the dmg file, select hardware from installer
select Network Link conditioner prefpane
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Hidden features of Perl?
...
One of my favourite features in Perl is using the boolean || operator to select between a set of choices.
$x = $a || $b;
# $x = $a, if $a is true.
# $x = $b, otherwise
This means one can write:
$x = $a || $b || $c || 0;
to take the first true value from $a, $b, and $c, or a default of 0...
Apache Prefork vs Worker MPM
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See also "How do I select which Apache MPM to use?" serverfault.com/a/383634
– Nazariy
Dec 18 '13 at 12:17
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How to convert TimeStamp to Date in Java?
... .atStartOfDay( ZoneId.of( "Africa/Tunis" ) )
.toEpochSecond()
…
"SELECT * FROM orders WHERE placed >= ? AND placed < ? ; "
…
myPreparedStatement.setObject( 1 , start )
myPreparedStatement.setObject( 2 , stop )
java.time
You are using troublesome old date-time classes that are...
How can I disable editing cells in a WPF Datagrid?
...into edit mode. I want to prevent that. Instead I want users to be able to select the full row - not edit values in it.
4 ...
How add “or” in switch statements?
...sizes: 1=Small 2=Medium 3=Large");
Console.Write("Please enter your selection: ");
string s = Console.ReadLine();
int n = int.Parse(s);
int cost = 0;
switch(n)
{
case 1:
cost += 25;
break;
...
How to use glOrtho() in OpenGL?
...0, 1.5, 20.0);
}
glMatrixMode(GL_MODELVIEW);
}
int main(int argc, char** argv) {
glutInit(&argc, argv);
if (argc > 1) {
ortho = 1;
}
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(500, 500);
glutInitWindowPosition(100, 100);
glutCr...
Sublime Text 2 and 3: open the same file multiple times
... the file in.
Type Ctrl-p (Mac: ⌘-p) to get the list of files available.
Select the one you're after and it will be loaded into the current pane
(Even if it's already open in another pane.)
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A Better Django Admin ManyToMany Field Widget
...lt models.ManyToManyField widget to be cumbersome to use. It's the HTML select element and if you have a lot of Objects of the "other" model then it's quite impractical to actually find the "other" Objects you want to associate with "this" Object. And if you have a lot of objects of the "other...