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Django select only rows with duplicate field values
...ne these into a single query:
Literal.objects.filter(name__in=dups)
The extra call to .values('name') after the annotate call looks a little strange. Without this, the subquery fails. The extra values tricks the ORM into only selecting the name column for the subquery.
...
“tag already exists in the remote" error after recreating the git tag
...lete push.
The remote may or may not allow tag deletion (depending on any extra hooks added). If it allows the deletion, then the tag will be gone, and a second git push --tags, when you have a local dev tag pointing to some commit or annotated tag repo object, send your new dev tag. On the remot...
How to use the C socket API in C++ on z/OS
...socklen_t sock_len;
private struct sockaddr_in server_addr;
public char *server_ip;
public unsigned short server_port;
};
Then have methods for opening, closing, and sending packets down the socket.
For example, the open call might look something like this:
int my_socket_connect()
{
...
When do I use the PHP constant “PHP_EOL”?
...
PHP_EOL (string)
The correct 'End Of Line' symbol for this platform.
Available since PHP 4.3.10 and PHP 5.0.2
You can use this constant when you read or write text files on the server's filesystem.
Line endings do not matter in...
Hidden features of Windows batch files
...
I was looking for this last week! (couldn't remember the character)
– chilltemp
Nov 11 '08 at 22:14
21
...
Becoming better at Vim [closed]
...nsciously use it as a navigation tool. The searches [/, ?] and the inline char based searc
How to check if an intent can be handled from some activity?
...n intent is not available,
fun isIntentAvailable(context: Context, action: String?): Boolean {
val packageManager = context.packageManager
val intent = Intent(action)
val resolveInfo: List<*> = packageManager.queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY)
retu...
What's the difference between a single precision and double precision floating point operation?
...s 32 bits, its double-precision counterpart will be 64 bits long.
The extra bits increase not only the precision but also the range of magnitudes that can be represented.
The exact amount by which the precision and range of magnitudes are increased depends on what format the program is using ...
The necessity of hiding the salt for a hash
..." is that it makes cracking more difficult, but it doesn't try to hide the extra data. If you are trying to get more security by making the salt "secret", then you really just want more bits in your encryption keys.
share
...
When to use lambda, when to use Proc.new?
...om :0
irb(main):006:0> p.call "hello"
TypeError: can't convert nil into String
from (irb):2:in `+'
from (irb):2
from (irb):6:in `call'
from (irb):6
from :0
The page also recommends using lambda unless you specifically want the error tolerant behavior. I agree with this senti...