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Why is enum class preferred over plain enum?
...this is usually an int. Also each enumerated type shall be compatible with char or a signed/unsigned integer type.
This is a wide description of what an enum underlying type must be, so each compiler will take decisions on his own about the underlying type of the classic enum and sometimes the resu...
The SQL OVER() clause - when and why is it useful?
...ated values and then join it back to the original rowset, i.e. like this:
SELECT
orig.[Partition],
orig.Value,
orig.Value * 100.0 / agg.TotalValue AS ValuePercent
FROM OriginalRowset orig
INNER JOIN (
SELECT
[Partition],
SUM(Value) AS TotalValue
FROM OriginalRowset
G...
How to unescape HTML character entities in Java?
...ally I would like to decode a given Html document, and replace all special chars, such as " " -> " " , ">" -> ">" .
...
How to check whether a file is empty or not?
... my_file.seek(0) #ensure you're at the start of the file..
... first_char = my_file.read(1) #get the first character
... if not first_char:
... print "file is empty" #first character is the empty string..
... else:
... my_file.seek(0) #first character wasn't empty, retu...
Best way to create unique token in Rails?
...ittle bit of code in his Railscast on beta invitations. This produces a 40 character alphanumeric string.
Digest::SHA1.hexdigest([Time.now, rand].join)
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Search text in stored procedure in SQL Server
...t the schema name by adding SCHEMA_NAME(o.schema_id) AS Schema_Name to the select clause.
– patricus
Jul 7 '16 at 15:07
6
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Count Rows in Doctrine QueryBuilder
...
Something like:
$qb = $entityManager->createQueryBuilder();
$qb->select('count(account.id)');
$qb->from('ZaysoCoreBundle:Account','account');
$count = $qb->getQuery()->getSingleScalarResult();
Some folks feel that expressions are somehow better than just using straight DQL. One...
python list in sql query as parameter
...I paramstyle.
placeholders= ', '.join(placeholder for unused in l)
query= 'SELECT name FROM students WHERE id IN (%s)' % placeholders
cursor.execute(query, l)
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Set selected index of an Android RadioGroup
Is there a way to set the selected index of a RadioGroup in android, other than looping through the child radiobuttons and selecting checking the radio button at the selected index?
...
NOT IN vs NOT EXISTS
...llow NULLs the NOT IN will be treated identically to the following query.
SELECT ProductID,
ProductName
FROM Products p
WHERE NOT EXISTS (SELECT *
FROM [Order Details] od
WHERE p.ProductId = od.ProductId)
The exact plan may vary but for my examp...