大约有 45,000 项符合查询结果（耗时：0.0780秒） [XML]
What is the most efficient/elegant way to parse a flat table into a tree?
..., we can say that all popular SQL databases support recursive queries in standard syntax.
WITH RECURSIVE MyTree AS (
SELECT * FROM MyTable WHERE ParentId IS NULL
UNION ALL
SELECT m.* FROM MyTABLE AS m JOIN MyTree AS t ON m.ParentId = t.Id
)
SELECT * FROM MyTree;
I tested recursive que...
Why is it impossible to override a getter-only property and add a setter? [closed]
...nly property. It doesn't make sense for derivations to break this contract and make it read-write.
I'm with Microsoft on this one.
Let's say I'm a new programmer who has been told to code against the Baseclass derivation. i write something that assumes that Bar cannot be written to (since the Basec...
Indenting code in Sublime text 2?
...press Ctrl + K + D to indent everything so the code is structured nicely and readable. Is there a shortcut in Sublime 2 to do the same?
...
How to move columns in a MySQL table?
...the structure view of a table.
Check to select the column you want to move and click the change action at the bottom of the column list.
You can then change all of the column properties and you'll find the 'move column' function at the far right of the screen.
Of course this is all just building th...
PHP code to convert a MySQL query to CSV [closed]
...
Among above two which one is better, safer and why?
– Chella
Jul 25 '14 at 7:25
1
...
How do I check if a string contains another string in Objective-C?
...");
}
The key is noticing that rangeOfString: returns an NSRange struct, and the documentation says that it returns the struct {NSNotFound, 0} if the "haystack" does not contain the "needle".
And if you're on iOS 8 or OS X Yosemite, you can now do: (*NOTE: This WILL crash your app if this code ...
How do you clone a Git repository into a specific folder?
Executing the command git clone git@github.com:whatever creates a directory in my current folder named whatever , and drops the contents of the Git repository into that folder:
...
Angularjs prevent form submission when input validation fails
...gularjs with some client side input validation to check that the user name and password is not empty and longer than three characters. See the below code:
...
Can we instantiate an abstract class?
... are creating an instance of an anonymous subclass of your abstract class. And then you are invoking the method on your abstract class reference pointing to subclass object.
This behaviour is clearly listed in JLS - Section # 15.9.1: -
If the class instance creation expression ends in a class b...
Add 10 seconds to a Date
...her Date functions, you should check out MDN
setSeconds will correctly handle wrap-around cases:
var d;
d = new Date('2014-01-01 10:11:55');
alert(d.getMinutes() + ':' + d.getSeconds()); //11:55
d.setSeconds(d.getSeconds() + 10);
alert(d.getMinutes() + ':0' + d.getSeconds()); //12:05
...