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Difference between CTE and SubQuery?
...
CTE's are most useful for recursion:
WITH hier(cnt) AS (
SELECT 1
UNION ALL
SELECT cnt + 1
FROM hier
WHERE cnt < @n
)
SELECT cnt
FROM hier
will return @n rows (up to 101). Useful for calendars, dummy rowsets etc.
They are als...
Do htmlspecialchars and mysql_real_escape_string keep my PHP code safe from injection?
...nerable to certain attack vectors.
Imagine the following SQL:
$result = "SELECT fields FROM table WHERE id = ".mysql_real_escape_string($_POST['id']);
You should be able to see that this is vulnerable to exploit.
Imagine the id parameter contained the common attack vector:
1 OR 1=1
There's no...
Python set to list
..., 'pop', 'remove', 'symmetric_difference', 'symmetric_difference_update', 'union', 'update'] (removed __ because of char limit)
– user825286
Jul 26 '11 at 10:48
...
Code Golf - π day
... area="{@area}"/>
</xsl:variable>
<xsl:apply-templates select="msxsl:node-set($next)"/>
</xsl:template>
<!-- End of the line?-->
<xsl:template match="s[@x &gt; @R]">
<xsl:variable name="next">
<!-- Go to next line.-->
&l...
How to find the kth smallest element in the union of two sorted arrays?
...ithmic. (Here we are getting rid of half). In order to do that, we need to select one array whose one of the halves we can safely ignore. How do we do that? By confidently eliminating the half we know for sure is not going to have the kth element.
– lambdapilgrim
...
Remove duplicate elements from array in Ruby
...= [1, 2, 2, 3]
counts = Hash.new(0)
a.each { |v| counts[v] += 1 }
p counts.select { |v, count| count == 1 }.keys # [1, 3]
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byte[] to hex string [duplicate]
...);
}
static string LinqConcat(byte[] data)
{
return string.Concat(data.Select(b => b.ToString("X2")).ToArray());
}
static string LinqJoin(byte[] data)
{
return string.Join("",
data.Select(
bin => bin.ToString("X2")
).ToArray());
}
static string LinqAgg(b...
How do I print a double value with full precision using cout?
...int out the binary bits (or hex nybbles).
One way of doing that is using a union to type-pun the double to a integer and then printing the integer, since integers do not suffer from truncation or round-off issues. (Type punning like this is not supported by the C++ standard, but it is supported in C...
clang: how to list supported target architectures?
...
> llc -mattr=help
Available CPUs for this target:
amdfam10 - Select the amdfam10 processor.
athlon - Select the athlon processor.
athlon-4 - Select the athlon-4 processor.
athlon-fx - Select the athlon-fx processor.
athlon-mp - Select the athlon-mp processor...
I need to store postal codes in a database. How big should the column be?
...nce a block on one side of the street. To find a broader region, you would select the first half of the postal code. Having this information in a separate table really won't help anything and would be more complicated to maintain.
– RevNoah
Dec 2 '13 at 17:08
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