大约有 41,000 项符合查询结果（耗时：0.0268秒） [XML]
Select distinct using linq [duplicate]
...
myList.GroupBy(test => test.id)
.Select(grp => grp.First());
Edit: as getting this IEnumerable<> into a List<> seems to be a mystery to many people, you can simply write:
var result = myList.GroupBy(test => test.id)
.S...
Using LINQ to remove elements from a List
... {
StringBuilder builder = new StringBuilder();
char ch;
for( int i = 0; i < size; i++ )
{
ch = Convert.ToChar( Convert.ToInt32( Math.Floor( 26 * random.NextDouble() + 65 ) ) );
builder.Append( ch );
}
...
How to retrieve the current value of an oracle sequence without increment it?
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SELECT last_number
FROM all_sequences
WHERE sequence_owner = '<sequence owner>'
AND sequence_name = '<sequence_name>';
You can get a variety of sequence metadata from user_sequences, all_sequences and dba_...
Using $_POST to get select option value from HTML
I use select as below:
8 Answers
8
...
Weird Integer boxing in Java
... section 5.1.7:
If the value p being boxed is true,
false, a byte, a char in the range
\u0000 to \u007f, or an int or short
number between -128 and 127, then let
r1 and r2 be the results of any two
boxing conversions of p. It is always
the case that r1 == r2.
The discussion goes on...
Create a unique number with javascript time
...oString(36) + Math.random().toString(36).substr(2) That will give you a 19 character alphanumeric string which is a decent amount of entropy. Albeit half of it is predictable.
– Erik Pukinskis
Jul 30 '17 at 23:32
...
@synthesize vs @dynamic, what are the differences?
... [invocation setReturnValue:&obj];
}
}
@end
int main(int argc, char **argv)
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
Book *book = [[Book alloc] init];
printf("%s is written by %s\n", [book.title UTF8String], [book.author UTF8String]);
book.title = @"...
MySQL ON vs USING?
...n tables ON a column, a set of columns and even a condition. For example:
SELECT * FROM world.City JOIN world.Country ON (City.CountryCode = Country.Code) WHERE ...
USING is useful when both tables share a column of the exact same name on which they join. In this case, one may say:
SELECT ... FR...
Can we pass parameters to a view in SQL?
..., like:
CREATE FUNCTION v_emp (@pintEno INT)
RETURNS TABLE
AS
RETURN
SELECT * FROM emp WHERE emp_id=@pintEno;
This allows you to use it as a normal view, with:
SELECT * FROM v_emp(10)
share
|
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Get/pick an image from Android's built-in Gallery app programmatically
...
https://github.com/hanscappelle/SO-2169649
(note that the multiple file selection still needs work)
Single Picture Selection
With support for images from file explorers thanks to user mad.
public class BrowsePictureActivity extends Activity {
// this is the action code we use in our inten...