大约有 42,000 项符合查询结果（耗时：0.0202秒） [XML]
TCP vs UDP on video stream
...s clients is long due to the singularity of the event. Pre-recorded video-casts typically don't have as much of a problem with this because viewers stagger their replay activity; therefore TCP is more appropriate for replaying a video-on-demand.
IP multicast significantly reduces video bandwidth re...
Postgresql GROUP_CONCAT equivalent?
...ROM data_table
GROUP BY id_field
array_agg returns an array, but you can CAST that to text and edit as needed (see clarifications, below).
Prior to version 8.4, you have to define it yourself prior to use:
CREATE AGGREGATE array_agg (anyelement)
(
sfunc = array_append,
stype = anyarray,
...
Get int value from enum in C#
...
Just cast the enum, e.g.
int something = (int) Question.Role;
The above will work for the vast majority of enums you see in the wild, as the default underlying type for an enum is int.
However, as cecilphillip points out, enum...
PostgreSQL: How to change PostgreSQL user password?
...
This let the clear password in the user's postgresql command history.
– greg
Oct 4 '12 at 7:42
126
...
How can I obtain the element-wise logical NOT of a pandas Series?
...
NumPy is slower because it casts the input to boolean values (so None and 0 becomes False and everything else becomes True).
import pandas as pd
import numpy as np
s = pd.Series([True, None, False, True])
np.logical_not(s)
gives you
0 False
1 ...
How can I select the first day of a month in SQL?
...
The casting of a string (i.e. "5/1/2009") to datetime is certainly more legible but we found code a while back that would return the first of the month...
DECLARE @Date DATETIME
//...
SELECT DATEADD(mm, DATEDIFF(mm,0,@Date), 0)
...
How to extract filename.tar.gz file
...
As far as I can tell, the command is correct, ASSUMING your input file is a valid gzipped tar file. Your output says that it isn't. If you downloaded the file from the internet, you probably didn't get the entire file, try again.
Without more knowledge o...
Why does this code segfault on 64-bit architecture but work fine on 32-bit?
...
The cast to int* masks the fact that without the proper #include the return type of malloc is assumed to be int. IA-64 happens to have sizeof(int) < sizeof(int*) which makes this problem obvious.
(Note also that because of t...
convert double to int
What is the best way to convert a double to an int ? Should a cast be used?
10 Answers
...
c# why can't a nullable int be assigned null as a value [duplicate]
... null cannot be implicitly converted to int nor vice-versus, so an explict cast is necessary. Try this instead:
int? accom = (accomStr == "noval" ? (int?)null : Convert.ToInt32(accomStr));
share
|
...