大约有 43,000 项符合查询结果（耗时：0.0760秒） [XML]
Multi-statement Table Valued Function vs Inline Table Valued Function
...ke 'C_______' then the outer query did a sub-string and int conversion. ie Cast(Substring(2, 2) as int) as CompNo. All looks good except that sql server decided to put my Cast function before the results were filtered and so I get a mind scrambling conversion error. A multi statement table functio...
Tactics for using PHP in a high-load site
...gh to attain high server loads. Treat me as (sigh) an alien that has just landed on the planet, albeit one that knows PHP and a few optimisation techniques.
...
Enable 'xp_cmdshell' SQL Server
...ncedOptions int
declare @prevXpCmdshell int
select @prevAdvancedOptions = cast(value_in_use as int) from sys.configurations where name = 'show advanced options'
select @prevXpCmdshell = cast(value_in_use as int) from sys.configurations where name = 'xp_cmdshell'
if (@prevAdvancedOptions = 0)
begin...
Why is conversion from string constant to 'char*' valid in C but invalid in C++
...ion has been removed, an explicit conversion still works, so you can add a cast. I would not, however, consider this "fixing" the code.
Truly fixing the code requires changing the type of the pointer to the correct type:
char const *p = "abc"; // valid and safe in either C or C++.
As to why it w...
How to use Class in Java?
...is overriding the T declared at Class level;
//So There is no ClassCastException though a is not the type of T declared at MyClass<T>.
private <T> T myMethod1(Object a){
return (T) a;
}
//Runtime ClassCastException will be thrown if a is ...
Why should I care that Java doesn't have reified generics?
...
Type safety comes to mind. Downcasting to a parametrized type will always be unsafe without reified generics:
List<String> myFriends = new ArrayList();
myFriends.add("Alice");
getSession().put("friends", myFriends);
// later, elsewhere
List<Frien...
How do I split a string so I can access item x?
...
)
returns table
AS
return (
with tokens(p, a, b) AS (
select
cast(1 as bigint),
cast(1 as bigint),
charindex(@separator, @str)
union all
select
p + 1,
b + 1,
charindex(@separator, @str, b + 1)
from tokens
where b > 0
)
sele...
What is a handle in C++?
...ss HANDLE around as an opaque value.
In the code that uses the object, it casts the pointer to a real structure type and uses it:
int doSomething(HANDLE s, int a, int b) {
Something* something = reinterpret_cast<Something*>(s);
return something->doit(a, b);
}
Or it uses it a...
What's the difference between equal?, eql?, ===, and ==?
I am trying to understand the difference between these four methods. I know by default that == calls the method equal? which returns true when both operands refer to exactly the same object.
...
Why can I pass 1 as a short, but not the int variable i?
...soft.com/en-us/library/ybs77ex4(v=vs.71).aspx
As this page says, implicit casts from a bigger data type to short are only allowed for literals. The compiler can tell when a literal is out of range, but not otherwise, so it needs reassurance that you've avoided an out-of-range error in your program ...