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Convert Rows to columns using 'Pivot' in SQL Server
...9, 3, 87);
If your values are known, then you will hard-code the query:
select *
from
(
select store, week, xCount
from yt
) src
pivot
(
sum(xcount)
for week in ([1], [2], [3])
) piv;
See SQL Demo
Then if you need to generate the week number dynamically, your code will be:
DECLARE @c...
Pretty-print C++ STL containers
...t print a delimiter after the final item
template<typename T, typename TChar = char, typename TCharTraits = std::char_traits<TChar> >
class pretty_ostream_iterator : public std::iterator<std::output_iterator_tag, void, void, void, void>
{
public:
typedef TChar char_type;
ty...
How long is the SHA256 hash?
...
you can use this select statement to test it: SELECT length(to_base64(unhex(sha2('say hello to my little friend',256)))) , it is always 44 whatever the length of original string is.
– DrAhmedJava
Apr 9 '...
Why should hash functions use a prime number modulus?
...er of buckets. This is convenient and saves having to search around or pre-select a prime number of the right magnitude. So you rely on the hash function not to use even multipliers, which is generally a safe assumption. But you can still get occasional bad hashing behaviours based on hash functions...
Clang vs GCC for my Linux Development project
...4/include/g++-v4/ostream:112: note: candidates are: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>& (*)(std::basic_ostream<_CharT, _Traits>&)) [with _CharT = char, _Traits = std::char_...
Merging two arrays in .NET
...ew[] { 1, 2, 3, 4, 5 };
var arr2 = new[] { 6, 7, 8, 9, 0 };
var arr = arr1.Union(arr2).ToArray();
Keep in mind, this will remove duplicates. If you want to keep duplicates, use Concat.
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Verifying that a string contains only letters in C#
...
This assumes a latin alphabet, where Char.IsLetter allows for non-latin alphabets.
– Paul van Brenk
Jul 28 '09 at 7:31
5
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How to do a regular expression replace in MySQL?
...ositions and perform substring substitution and extraction, respectively.
SELECT REGEXP_REPLACE('Stackoverflow','[A-Zf]','-',1,0,'c');
-- Output:
-tackover-low
DBFiddle Demo
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What is a method that can be used to increment letters?
...
Simple, direct solution
function nextChar(c) {
return String.fromCharCode(c.charCodeAt(0) + 1);
}
nextChar('a');
As others have noted, the drawback is it may not handle cases like the letter 'z' as expected. But it depends on what you want out of it. The s...
Why the switch statement cannot be applied on strings?
...however this might not be so easy for strings (considering run-time locale selection and so on). I suppose that such a thing would have to require constexpr cases, or add in unspecified behaviour (never a thing that we want to do).
– M.M
Jun 11 '15 at 23:37
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