大约有 5,475 项符合查询结果（耗时：0.0284秒） [XML]
Why do I get “Procedure expects parameter '@statement' of type 'ntext/nchar/nvarchar'.” when I try t
...ill give the error because @SQL needs to be NVARCHAR
DECLARE @SQL VARCHAR(100)
SET @SQL = 'SELECT TOP 1 * FROM sys.tables'
EXECUTE sp_executesql @SQL
So:
DECLARE @SQL NVARCHAR(100)
SET @SQL = 'SELECT TOP 1 * FROM sys.tables'
EXECUTE sp_executesql @SQL
...
Is a LINQ statement faster than a 'foreach' loop?
...ee> items = new List<Employee>();
for (int i = 0; i < 10000000; i++)
{
items.Add(new Employee(i,"name" + i,"lastname" + i,DateTime.Today));
}
Test3(items, items.Count-100);
Test4(items, items.Count - 100);
Console.Read();
...
How to check if a number is a power of 2
...3) == 0)
But what exactly is 4&3?
The binary representation of 4 is 100 and the binary representation of 3 is 011 (remember the & takes the binary representation of these numbers). So we have:
100 = 4
011 = 3
Imagine these values being stacked up much like elementary addition. The &am...
What are database normal forms and can you give examples? [closed]
...
------------------------------------------------|
IT101 | 2009-1 | 100 | Programming |
IT101 | 2009-2 | 100 | Programming |
IT102 | 2009-1 | 200 | Databases |
IT102 | 2010-1 | 150 | Databases |
IT103 | 2009-2 | 120 | Web Design |...
Centering floating divs within another div
...t;/span>
</div>
with CSS:
.wpr
{
width: 400px;
height: 100px;
background: pink;
padding: 10px 30px;
}
.wpr span
{
width: 50px;
height: 50px;
background: green;
float: left; /* **children floated left** */
margin: 0 5px;
}
(This is the (expected - an...
How to determine whether a Pandas Column contains a particular value
...
I did a few simple tests:
In [10]: x = pd.Series(range(1000000))
In [13]: timeit 999999 in x.values
567 µs ± 25.6 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)
In [15]: timeit x.isin([999999]).any()
9.54 ms ± 291 µs per loop (mean ± std. dev. of 7 runs, 100 l...
Thread vs ThreadPool
...sts for new work items (I believe this is only in .NET 3.5)
If you queue 100 thread pool tasks, it will only use as many threads as have already been created to service these requests (say 10 for example). The thread pool will make frequent checks (I believe every 500ms in 3.5 SP1) and if there ar...
How to toggle a value in Python
... almost the fastest too
>>> stmt1="""
toggle=0
for i in xrange(0,100):
toggle = 1 if toggle == 0 else 0
"""
>>> stmt2="""
x=[1,0]
toggle=0
for i in xrange(0,100):
toggle=x[toggle]
"""
>>> t1=timeit.Timer(stmt=stmt1)
>>> t2=timeit.Timer(stmt=stmt2)
>>...
UDP vs TCP, how much faster is it? [closed]
... The most important thing TCP gives you is congestion control: you can run 100 TCP connections across a DSL link all going at max speed, and all 100 connections will be productive, because they all "sense" the available bandwidth. Try that with 100 different UDP applications, all pushing packets as ...
Easy interview question got harder: given numbers 1..100, find the missing number(s) given exactly k
I had an interesting job interview experience a while back. The question started really easy:
47 Answers
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