大约有 45,000 项符合查询结果（耗时：0.0190秒） [XML]
Fastest check if row exists in PostgreSQL
...
How about simply:
select 1 from tbl where userid = 123 limit 1;
where 123 is the userid of the batch that you're about to insert.
The above query will return either an empty set or a single row, depending on whether there are records with the given userid.
If this turns o...
How can I use a batch file to write to a text file?
...d in D:\Temp\WriteText.bat
@echo off
echo This is a test> test.txt
echo 123>> test.txt
echo 245.67>> test.txt
Output:
D:\Temp>WriteText
D:\Temp>type test.txt
This is a test
123
245.67
D:\Temp>
Notes:
@echo off turns off printing of each command to the console
Unless...
How do I get a list of all subdomains of a domain? [closed]
...
Correct command should be: dig @123.456.789.123 DOMAIN.COM -t axfr
– Superbiji
Jan 8 '14 at 7:48
8
...
TypeError: ObjectId('') is not JSON serializable
...
123
You should define you own JSONEncoder and using it:
import json
from bson import ObjectId
cl...
Printing the correct number of decimal points with cout
...lt;iomanip>
int main(int argc, char** argv)
{
float testme[] = { 0.12345, 1.2345, 12.345, 123.45, 1234.5, 12345 };
std::cout << std::setprecision(2) << std::fixed;
for(int i = 0; i < 6; ++i)
{
std::cout << testme[i] << std::endl;
}
re...
Install a Windows service using a Windows command prompt?
...
If the directory's name has a space like c:\program files\abc 123, then you must use double quotes around the path.
installutil.exe "c:\program files\abc 123\myservice.exe"
It makes things much easier if you set up a bat file like following,
e.g. To install a service, create a "my...
How do I work around JavaScript's parseInt octal behavior?
... Number needs quotes around the 08. Also just be warned, Number('08.123') will produce 8.123 as its output. If you really want an integer, don't use Number (or pattern-match your input to ensure integers only).
– Jason S
May 11 '09 at 22:22
...
Converting A String To Hexadecimal In Java
I am trying to convert a string like "testing123" into hexadecimal form in java. I am currently using BlueJ.
21 Answers
...
Press alt + numeric in bash and you get (arg [numeric]) what is that?
... + numeric and then you press a character, you'll get num caracters: (arg: 123) + a -> 123 times "a"
share
|
improve this answer
|
follow
|
...
How to pass command line arguments to a rake task
...something like this:
$ rake user:create -- --user test@example.com --pass 123
note the --, that's necessary for bypassing standard Rake arguments. Should work with Rake 0.9.x, <= 10.3.x.
Newer Rake has changed its parsing of --, and now you have to make sure it's not passed to the OptionParse...