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Insert into … values ( SELECT … FROM … )
...SERT from another table I did the following in SQLite3:
INSERT INTO column_1 ( val_1, val_from_other_table )
VALUES('val_1', (SELECT val_2 FROM table_2 WHERE val_2 = something))
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When do items in HTML5 local storage expire?
... localStorage.removeItem(name);
localStorage.removeItem(name + '_expiresIn');
} catch(e) {
console.log('removeStorage: Error removing key ['+ key + '] from localStorage: ' + JSON.stringify(e) );
return false;
}
return true;
}
/* getStorage: retrieves a key fro...
How to pass variable from jade template file to a script file?
...s how I addressed this (using a MEAN derivative)
My variables:
{
NODE_ENV : development,
...
ui_varables {
var1: one,
var2: two
}
}
First I had to make sure that the necessary config variables were being passed. MEAN uses the node nconf package, and by default is set up to li...
Why is my git repository so big?
... warnings;
use strict;
use IPC::Open2;
use v5.14;
# Try to get the "format_bytes" function:
my $canFormat = eval {
require Number::Bytes::Human;
Number::Bytes::Human->import('format_bytes');
1;
};
my $format_bytes;
if ($canFormat) {
$format_bytes = \&format_bytes;
}
else {
...
Sleep for milliseconds
... facilities:
#include <chrono>
#include <thread>
std::this_thread::sleep_for(std::chrono::milliseconds(x));
Clear and readable, no more need to guess at what units the sleep() function takes.
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select、poll、epoll之间的区别总结[整理] - C/C++ - 清泛网 - 专注C/C++及内核技术
...1、select实现
select的调用过程如下所示：
（1）使用copy_from_user从用户空间拷贝fd_set到内核空间
（2）注册回调函数__pollwait
（3）遍历所有fd，调用其对应的poll方法（对于socket，这个poll方法是sock_poll，sock_poll根据情况会调用到...
How to export table as CSV with headings on Postgresql?
...
COPY products_273 TO '/tmp/products_199.csv' WITH (FORMAT CSV, HEADER);
as described in the manual.
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How do I access command line arguments in Python?
...a small example:
import argparse
parser = argparse.ArgumentParser("simple_example")
parser.add_argument("counter", help="An integer will be increased by 1 and printed.", type=int)
args = parser.parse_args()
print(args.counter + 1)
and the output for python prog.py -h
usage: simple_example [-h] ...
List comprehension: Returning two (or more) items for each item
...bda x: x + 2
>>> g = lambda x: x ** 2
>>> list(chain.from_iterable((f(x), g(x)) for x in range(3)))
[2, 0, 3, 1, 4, 4]
Timings:
from timeit import timeit
f = lambda x: x + 2
g = lambda x: x ** 2
def fg(x):
yield f(x)
yield g(x)
print timeit(stmt='list(chain.from_itera...
How to convert ActiveRecord results into an array of hashes
...
as_json
You should use as_json method which converts ActiveRecord objects to Ruby Hashes despite its name
tasks_records = TaskStoreStatus.all
tasks_records = tasks_records.as_json
# You can now add new records and return the...