大约有 40,000 项符合查询结果（耗时：0.0200秒） [XML]
SQL query for finding records where count > 1
...p int(11) not null,
dt date not null
);
insert into payment values
(1,123,55555,'2009-12-12'),
(1,123,66666,'2009-12-12'),
(1,123,77777,'2009-12-13'),
(2,456,77777,'2009-12-14'),
(2,456,77777,'2009-12-14'),
(2,789,77777,'2009-12-14'),
(2,789,77777,'2009-12-14');
select foo.user_id, foo.cnt fro...
C# short/long/int literal format?
...by F or f is of type float. For example, the literals 1f, 1.5f, 1e10f, and 123.456F are all of type float.
A real literal suffixed by D or d is of type double. For example, the literals 1d, 1.5d, 1e10d, and 123.456D are all of type double.
A real literal suffixed by M or m is of type decimal. For ex...
How to use cURL to get jSON data and decode the data?
...wer your question :P
$url="https://.../api.php?action=getThreads&hash=123fajwersa&node_id=4&order_by=post_date&order=desc&limit=1&grab_content&content_limit=1";
Using cURL
// Initiate curl
$ch = curl_init();
// Will return the response, if false it print the re...
How to remove unused imports from Eclipse
...swered Mar 26 '13 at 6:24
niknik123niknik123
18111 silver badge77 bronze badges
...
java.util.regex - importance of Pattern.compile()?
...ch is really called a lot :)
public class AmountValidator {
//Accept 123 - 123,456 - 123,345.34
private static final String AMOUNT_REGEX="\\d{1,3}(,\\d{3})*(\\.\\d{1,4})?|\\.\\d{1,4}";
//Compile and save the pattern
private static final Pattern AMOUNT_PATTERN = Pattern.compile(AM...
Remove duplicated rows using dplyr
...ction for this purpose.
Original answer below:
library(dplyr)
set.seed(123)
df <- data.frame(
x = sample(0:1, 10, replace = T),
y = sample(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_nu...
Password hint font in Android
...ord.setTypeface(cache);
Testing
Some device face font problem
Xiaomi A2 (8.0.1)
Pixel XL (8.1.0)
Sony Xperia Z5 Au (SOV32) (6.0)
Arrow NX (F-04G) (6.0.1)
Kyocera (S2) (7.0)
Some device not face font problem
Samsung S4 (SC-04E) (5.0.1)
Samsung Galaxy Node 5 (5.1.1)
Samsung S7 Edge (SM-G935F...
What is boxing and unboxing and what are the trade offs?
...xing is the conversion of a reference type into a value type.
EX: int i = 123;
object o = i;// Boxing
int j = (int)o;// UnBoxing
Value Types are: int, char and structures, enumerations.
Reference Types are:
Classes,interfaces,arrays,strings and objects
...
sed: print only matching group
...it with a 2nd grep.
# To extract \1 from /xx([0-9]+)yy/
$ echo "aa678bb xx123yy xx4yy aa42 aa9bb" | grep -Eo 'xx[0-9]+yy' | grep -Eo '[0-9]+'
123
4
# To extract \1 from /a([0-9]+)b/
$ echo "aa678bb xx123yy xx4yy aa42 aa9bb" | grep -Eo 'a[0-9]+b' | grep -Eo '[0-9]+'
678
9
...
Dynamic SQL - EXEC(@SQL) versus EXEC SP_EXECUTESQL(@SQL)
...
EXEC('SELECT * FROM FOO WHERE ID=?', 123) will replace the parameter placeholder "?" with the value 123 and then execute the query, returning a result for SELECT * FROM FOO WHERE ID=123
– Peter Wone
Jun 1 '10 at 23:27
...