大约有 47,000 项符合查询结果（耗时：0.0444秒） [XML]
Linq: GroupBy, Sum and Count
...
I don't understand where the first "result with sample data" is coming from, but the problem in the console app is that you're using SelectMany to look at each item in each group.
I think you just want:
List<ResultLine> result = Lin...
Differences between Java 8 Date Time API (java.time) and Joda-Time
I know there are questions relating to java.util.Date and Joda-Time. But after some digging, I couldn't find a thread about the differences between the java.time API (new in Java 8 , defined by JSR 310 ) and Joda-Time .
...
Remove duplicated rows using dplyr
...mple(0:1, 10, replace = T),
z = 1:10
)
One approach would be to group, and then only keep the first row:
df %>% group_by(x, y) %>% filter(row_number(z) == 1)
## Source: local data frame [3 x 3]
## Groups: x, y
##
## x y z
## 1 0 1 1
## 2 1 0 2
## 3 1 1 4
(In dplyr 0.2 you won't need...
How to iterate over a JavaScript object?
...{
console.log(key, yourobject[key]);
}
With ES6, if you need both keys and values simultaneously, do
for (let [key, value] of Object.entries(yourobject)) {
console.log(key, value);
}
To avoid logging inherited properties, check with hasOwnProperty :
for (let key in yourobject) {
if (y...
How do you make an array of structs in C?
... a question about the placement between the declaration of the struct type and then actually making an instance of it - I have a different struct, one that I defined the contents of below where I first make an instance of it (just one this time, not an array), so why didn't this make the massive ser...
How to show and update echo on same line
...hat could do this if I added a 3rd escape character.
The 2 options are -n and -e.
-n will not output the trailing newline. So that saves me from going to a new line each time I echo something.
-e will allow me to interpret backslash escape symbols.
Guess what escape symbol I want to use for this...
Using curl POST with variables defined in bash script functions
...script. This saves you from all sort of headaches concerning shell quoting and makes it easier to read an maintain the script than feeding the post data on curl's invocation line as in your attempt:
generate_post_data()
{
cat <<EOF
{
"account": {
"email": "$email",
"screenName": "...
Error executing command 'ant' on Mac OS X 10.9 Mavericks when building for Android with PhoneGap/Cor
...th Mac OS X Mavericks . Building for iOS went just fine, but building for Android wasn't without some guesswork.
7 Answers...
brew install mysql on macOS
...ion with older versions of mysql already installed. I had the same problem and none of the above solutions worked for me. I fixed it thus:
Used brew's remove & cleanup commands, unloaded the launchctl script, then deleted the mysql directory in /usr/local/var, deleted my existing /etc/my.cnf (l...
Eclipse - java.lang.ClassNotFoundException
...
I've come across that situation several times and, after a lot of attempts, I found the solution.
Check your project build-path and enable specific output folders for each folder. Go one by one though each source-folder of your project and set the output folder that mav...