大约有 16,000 项符合查询结果（耗时：0.0254秒） [XML]
How to DROP multiple columns with a single ALTER TABLE statement in SQL Server?
...bleName
DROP COLUMN Column1, Column2;
The syntax is
DROP { [ CONSTRAINT ] constraint_name | COLUMN column } [ ,...n ]
For MySQL:
ALTER TABLE TableName
DROP COLUMN Column1,
DROP COLUMN Column2;
or like this1:
ALTER TABLE TableName
DROP Column1,
DROP Column2;
1 The wo...
How to create a MySQL hierarchical recursive query
...ditions in this where clause are evaluated in order, and the evaluation is interrupted once the total outcome is certain. Therefore the second condition must be in second place, as it adds the id to the parent list, and this should only happen if the id passes the first condition. The length functio...
Post-increment and pre-increment within a 'for' loop produce same output [duplicate]
...
Well, this is simple. The above for loops are semantically equivalent to
int i = 0;
while(i < 5) {
printf("%d", i);
i++;
}
and
int i = 0;
while(i < 5) {
printf("%d", i);
++i;
}
Note that the lines i++; and ++i; have the same semantics FROM THE PERSPECTIVE OF THIS BLOCK O...
How to get a file or blob from an object URL?
...her methods. When an image is dropped, I'm using URL.createObjectURL to convert to an object URL to display the image. I am not revoking the url, as I do reuse it.
...
Resizing an Image without losing any quality [closed]
...mage(newImage))
{
gr.SmoothingMode = SmoothingMode.HighQuality;
gr.InterpolationMode = InterpolationMode.HighQualityBicubic;
gr.PixelOffsetMode = PixelOffsetMode.HighQuality;
gr.DrawImage(srcImage, new Rectangle(0, 0, newWidth, newHeight));
}
...
Lambda capture as const reference?
...
Also, perhaps this should be edited into the accepted answer? Either way, there should be one good answer that covers both c++11 and c++14. Although, I guess it could be argued that c++14 will be good enough for everyone over the coming years
...
Weighted random numbers
...om number is less than that item's weight
Pseudo-code illustrating this:
int sum_of_weight = 0;
for(int i=0; i<num_choices; i++) {
sum_of_weight += choice_weight[i];
}
int rnd = random(sum_of_weight);
for(int i=0; i<num_choices; i++) {
if(rnd < choice_weight[i])
return i;
rnd -...
Which MySQL data type to use for storing boolean values
...st evaluated as integer (decimal and float values are rounded, strings are converted in the usual quirky way MySQL converts strings to integer). A NULL is obviously NULL (neither TRUE nor FALSE). An integer value of 0 is handled as FALSE, and any other integer value (1, 2, -7, etc) evaluates to TRUE...
Get string between two strings in a string
...= "super exemple of string key : text I want to keep - end of my string";
int pFrom = St.IndexOf("key : ") + "key : ".Length;
int pTo = St.LastIndexOf(" - ");
String result = St.Substring(pFrom, pTo - pFrom);
share
...
How to document a method with parameter(s)?
...ority: The priority of the message, can be a number 1-5
:type priority: integer or None
:return: the message id
:rtype: int
:raises ValueError: if the message_body exceeds 160 characters
:raises TypeError: if the message_body is not a basestring
'''
This markup supports cross-ref...