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How do I create a unique constraint that also allows nulls?
...et_AllowNull
UNIQUE (TicketID, TicketUnique);
If IssueID 1 has ticket 123, the UNIQUE constraint will be on values (123, NULL). If IssueID 2 has no ticket, it will be on (NULL, 2). Some thought will show that this constraint cannot be duplicated for any row in the table, and still allows multip...
Is JavaScript an untyped language?
...licit compiler interjection, the instruction will error during run-time.
"12345" * 1 === 12345 // string * number => number
Strongly typed means there is a compiler, and it wants you an explicit cast from string to integer.
(int) "12345" * 1 === 12345
In either case, some compiler's featur...
import module from string variable
...ike importlib.import_module("feature.email")
– Seanny123
Dec 6 '13 at 7:13
11
Finally, also remem...
Should struct definitions go in .h or .c file?
...r version:
#include "api.h"
void good(struct s *foo)
{
api_func(foo, 123);
}
This one pokes around in the implementation details:
#include "api.h"
void bad(struct s *foo)
{
foo->internal = 123;
}
which will work with the "definition in header" version, but not with the "definition...
How to measure time taken by a function to execute
...returns the number of microseconds in the fractional (e.g. a value of 1000.123 is 1 second and 123 microseconds).
now() is monotonically increasing. This is important as Date.getTime() can possibly jump forward or even backward on subsequent calls. Notably, if the OS's system time is updated (e.g....
Regular expression for letters, numbers and - _
...et to show how you can use this pattern:
<?php
$arr = array(
'screen123.css',
'screen-new-file.css',
'screen_new.js',
'screen new file.css'
);
foreach ($arr as $s) {
if (preg_match('/^[\w.-]*$/', $s)) {
print "$s is a match\n";
} else {
print "$s is NO match!!!\n";
};
}
...
Application auto build versioning
...ice that full package name is required. go build -ldflags "-X pkg.version=123" won't work while go build -ldflags "-X path/to/pkg.version=123" work as expected. hope it helps.
– csyangchen
Nov 25 '15 at 9:04
...
What are the most-used vim commands/keypresses?
... blank line; } next blank line
By file:
gg start of file; G end of file
123G go to specific line number
By marker:
mx set mark x; 'x go to mark x
'. go to position of last edit
' ' go back to last point before jump
Scrolling:
^F forward full screen; ^B backward full screen
^D down half scre...
Get nested JSON object with GSON using retrofit
...s":"OK",
"reason":"some reason",
"content" :
{
"foo": 123,
"bar": "some value"
}
}
You'd then have a Content POJO:
class Content
{
public int foo;
public String bar;
}
Then you write a deserializer:
class MyDeserializer implements JsonDeserializer<Co...
Does Javascript pass by reference? [duplicate]
...cript!
Call-by-Value
Primitive types are passed by-value:
var num = 123, str = "foo";
function f(num, str) {
num += 1;
str += "bar";
console.log("inside of f:", num, str);
}
f(num, str);
console.log("outside of f:", num, str);
Reassignments inside a function scope are ...