大约有 41,000 项符合查询结果（耗时：0.0362秒） [XML]
What is “rvalue reference for *this”?
...
If a class instance is not const, overload resolution will preferentially select the non-const version. If the instance is const, the user can only call the const version. And the this pointer is a const pointer, so the instance cannot be changed.
What "r-value reference for this` does is allow yo...
Number of rows affected by an UPDATE in PL/SQL
... block, this can be achieved.
... If anyone has a solution to use it in a SELECT Command, I would be interested.
share
|
improve this answer
|
follow
|
...
Quickly reading very large tables as dataframes
...
# sqldf as on SO
f <- file("test.csv")
system.time(SQLf <- sqldf("select * from f", dbname = tempfile(), file.format = list(header = T, row.names = F)))
## user system elapsed
## 10.21 0.47 10.73
ff / ffdf
require(ff)
system.time(FFDF <- read.csv.ffdf(file="test.csv",nro...
Disabling Chrome cache for website development
...ck (or hold left click) on the reload button at the top of the browser and select "Empty Cache and Hard Reload."
This will go beyond "Hard Reload" to empty the cache entirely, ensuring that anything downloaded via javascript or etc. will also avoid using the cache. You don't have to mess with set...
How do I put double quotes in a string in vba?
...ring
Dim objDataObj As Object
'\Check that single cell is selected!
If Selection.Cells.Count > 1 Then
MsgBox "Select single cell only!", vbCritical
Exit Sub
End If
'Check if we are not on a blank cell!
If Len(ActiveCell.Formu...
Turning a Comma Separated string into individual rows
... SomeID INT,
OtherID INT,
String VARCHAR(MAX)
)
INSERT Testdata SELECT 1, 9, '18,20,22'
INSERT Testdata SELECT 2, 8, '17,19'
INSERT Testdata SELECT 3, 7, '13,19,20'
INSERT Testdata SELECT 4, 6, ''
INSERT Testdata SELECT 9, 11, '1,2,3,4'
The query
;WITH tmp(SomeID, OtherID, DataIt...
How do I remove a project configuration in Visual Studio 2008?
...
In the Configuration Manager, select "Edit..." in the "Configuration" column for each project (not via the dropdown named Active solution configuration) that has configurations you want to remove.
In the dialog that pops up, mark each unwanted configurat...
What exactly is nullptr?
...rloading a function for both pointers and integers, and passing nullptr to select the pointer version. Passing NULL or 0 would confusingly select the int version.
A cast of nullptr_t to an integral type needs a reinterpret_cast, and has the same semantics as a cast of (void*)0 to an integral type (...
Unique random string generation
...ncat(
Enumerable
.Repeat(0, int.MaxValue)
.Select(e => RandomByte())
.Where(randomByte => randomByte < outOfRange)
.Take(length)
.Select(randomByte => alphabet[randomByte % alphabet.Length])
);
}
byte RandomByte()
{...
Print all but the first three columns
...ents. We have asked the OP to choose a more correct answer, and he/she has selected mine. After some other contributors have edited my answer to reference there answer (see the history). Is it clear for you? What do you advice me to improve the understandability of my answer? Cheers ;-)
...