大约有 43,100 项符合查询结果（耗时：0.0559秒） [XML]
Find rows that have the same value on a column in MySQL
...SELECT email,
count(*) AS c
FROM TABLE
GROUP BY email
HAVING c > 1
ORDER BY c DESC
If you want the full rows:
select * from table where email in (
select email from table
group by email having count(*) > 1
)
...
How to use shared memory with Linux in C
...
166
There are two approaches: shmget and mmap. I'll talk about mmap, since it's more modern and fl...
PHP: How to send HTTP response code?
...TP response line and lets you replace that with a custom one
header("HTTP/1.1 200 OK");
However, this requires special treatment for (Fast)CGI PHP:
$sapi_type = php_sapi_name();
if (substr($sapi_type, 0, 3) == 'cgi')
header("Status: 404 Not Found");
else
header("HTTP/1.1 404 Not Found");...
Can't pickle when using multiprocessing Pool.map()
...
12 Answers
12
Active
...
How to define a function in ghci across multiple lines?
...
125
For guards (like your example), you can just put them all on one line and it works (guards do ...
snprintf and Visual Studio 2010
I'm unfortunate enough to be stuck using VS 2010 for a project, and noticed the following code still doesn't build using the non-standards compliant compiler:
...
EC2 Can't resize volume after increasing size
...
14 Answers
14
Active
...
Numpy matrix to array
I am using numpy. I have a matrix with 1 column and N rows and I want to get an array from with N elements.
9 Answers
...
How to pick a new color for each plotted line within a figure in matplotlib?
...
matplotlib 1.5+
You can use axes.set_prop_cycle (example).
matplotlib 1.0-1.4
You can use axes.set_color_cycle (example).
matplotlib 0.x
You can use Axes.set_default_color_cycle.
...