大约有 31,100 项符合查询结果（耗时：0.0355秒） [XML]
Group by month and year in MySQL
...
Performance... my test of GROUP BY YEAR(date), MONTH(date) DESC; (~450 ms) and GROUP BY DATE_FORMAT(date,'%Y-%m') (~850 ms) on a InnoDB table with > 300,000 entries showed the former (the marked answer to this question) took ~half the ti...
How to redirect output with subprocess in Python?
...couraged, albeit still available in Python 3.
Use os.system:
os.system(my_cmd)
If you really want to use subprocess, here's the solution (mostly lifted from the documentation for subprocess):
p = subprocess.Popen(my_cmd, shell=True)
os.waitpid(p.pid, 0)
OTOH, you can avoid system calls enti...
How often should you use git-gc?
...in the future. The fact that git keeps most of its debris around has saved my bacon several times – by browsing all the dangling commits, I have recovered much work that I had accidentally canned.
So don’t be too much of a neat freak in your private clones. There’s little need for it.
OTOH, ...
What are the use cases for selecting CHAR over VARCHAR in SQL?
I realize that CHAR is recommended if all my values are fixed-width. But, so what? Why not just pick VARCHAR for all text fields just to be safe.
...
#include in .h or .c / .cpp?
...
@BrendanLong I see, although in my sense including several times a same header doesn't matter if you put the correct macros inside to include the content only once. Therefore, I think that putting even less is to reduce probabilities to get an error in the ...
Use URI builder in Android or create URL with variables
I'm developing an Android app. I need to build a URI for my app to make an API request. Unless there's another way to put a variable in a URI, this is the easiest way I've found. I found that you need to use Uri.Builder , but I'm not quite sure how to. My url is:
...
The calling thread must be STA, because many UI components require this
...
Yeahhh, you guys saved my life!!
– Alex McManns
Mar 30 '16 at 8:22
12
...
Equals(=) vs. LIKE
... operators produce obviously different results. Allow me to quote from the MySQL manual:
Per the SQL standard, LIKE performs matching on a per-character basis, thus it can produce results different from the = comparison operator:
mysql> SELECT 'ä' LIKE 'ae' COLLATE latin1_german2_ci;
+----...
Python 3 turn range to a list
...
You can just construct a list from the range object:
my_list = list(range(1, 1001))
This is how you do it with generators in python2.x as well. Typically speaking, you probably don't need a list though since you can come by the value of my_list[i] more efficiently (i + 1), a...
Remove the legend on a matplotlib figure
... For some reason, the ax.get_legend().remove() solution did not work in my case, while the second solution (legend = ax.legend() ... legend.remove()) worked. maybe because ax was an AxesSubplot in my case?
– jhin
Jan 16 '19 at 18:59
...