大约有 43,000 项符合查询结果（耗时：0.0435秒） [XML]
Postgres unique constraint vs index
...violates unique constraint "master_con_id_key"
DETAIL: Key (con_id)=(0) already exists.
test=# insert into master values (1, 0);
ERROR: duplicate key value violates unique constraint "master_unique_idx"
DETAIL: Key (ind_id)=(0) already exists.
test=#
It works as expected!
Foreign keys
Now we'...
Android - How to get application name? (Not package name)
...
while reading App Name from string.xml, sometimes, am getting junk characters. I dont know why ..Ex: स्कैनर
– harikrishnan
Oct 17 '16 at 9...
Syntax for a single-line Bash infinite while loop
...dition has an exit status which is not zero.
Using a while loop:
while read i; do foo; sleep 2; done < /dev/urandom
Using a for loop:
for ((;;)); do foo; sleep 2; done
Another way using until:
until [ ]; do foo; sleep 2; done
...
How can I stop a running MySQL query?
... then I run a SELECT query that is too big. It prints and prints and I already know this is not what I meant. I would like to stop the query.
...
Extracting text OpenCV
...}
return boundRect;
}
Usage:
int main(int argc,char** argv)
{
//Read
cv::Mat img1=cv::imread("side_1.jpg");
cv::Mat img2=cv::imread("side_2.jpg");
//Detect
std::vector<cv::Rect> letterBBoxes1=detectLetters(img1);
std::vector<cv::Rect> letterBBoxes2=detectLe...
Use of 'const' for function parameters
... and mark parameters const whenever possible; it's more expressive. When I read someone else's code, I use little indicators like this to judge how much care they put into writing their code alongside things like magic numbers, commenting, and proper pointer usage, etc.
– Ultim...
How to disable an Android button?
...
@Poldie: Actually, if you read the two answers you will understand they are pretty similar but not equal.
– Paolo Rovelli
Feb 5 '14 at 14:45
...
How to get the response of XMLHttpRequest?
...
You can get it by XMLHttpRequest.responseText in XMLHttpRequest.onreadystatechange when XMLHttpRequest.readyState equals to XMLHttpRequest.DONE.
Here's an example (not compatible with IE6/7).
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
if (xhr.readyState == X...
How to generate a random number in C++?
...plementation) then you will get exactly the same sequence of rand() values read after that in both applications.
However in your example application pseudo-random sequence consists only of one element - the first element of a pseudo-random sequence generated from seed equal to current time of second...
How do I access my SSH public key?
...l cat ~/.ssh/id_rsa.pub
explanation
cat is a standard Unix utility that reads files and prints output
~ Is your Home User path
/.ssh - your hidden directory contains all your ssh certificates
id_rsa.pub OR id_dsa.pub are RSA public keys, (the private key located on the client machine). the primar...