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JPA: How to have one-to-many relation of the same Entity type
...);
em.persist(son);
em.persist(daughter);
em.getTransaction().commit();
}
In this case, all three entity instances must be persisted before transaction commit. If I fail to persist one of the entities in the graph of parent-child relationships, then an exception is thrown on commit()...
What makes a keychain item unique (in iOS)?
... a keychain item of class kSecClassGenericPassword, the primary key is the combination of
kSecAttrAccount and kSecAttrService.
For a keychain item of class kSecClassInternetPassword, the primary key is the combination of kSecAttrAccount, kSecAttrSecurityDomain, kSecAttrServer, kSecAttrProtocol, kSe...
Bash set +x without it being printed
...em, and I was able to find a solution that doesn't use a subshell:
set -x
command
{ set +x; } 2>/dev/null
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Understanding exactly when a data.table is a reference to (vs a copy of) another data.table
... saw for DT above. Type example(copy) for more examples using tracemem and comparison to data.frame.
Btw, if you tracemem(DT) then DT[2,b:=600] you'll see one copy reported. That is a copy of the first 10 rows that the print method does. When wrapped with invisible() or when called within a functio...
Should I use the datetime or timestamp data type in MySQL?
Would you recommend using a datetime or a timestamp field, and why (using MySQL)?
39 Answers
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IIS Express Immediately shutting-down running site after stopping web application
... you can read about this feature in more details here: blogs.msdn.com/b/webdev/archive/2013/07/11/…
– gor
Jan 21 '14 at 16:46
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Checking if an instance's class implements an interface?
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Add a CSS class to
... add class without removing default value answer here stackoverflow.com/questions/8811254/…
– Naoise Golden
Oct 16 '12 at 10:33
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What is a Lambda?
... not necessarily have to be closures, but they are in most languages and become rather less useful when they aren't.
A lambda is.. not quite so well defined as far as computer science goes. A lot of languages don't even use the term; instead they will just call them closures or anon functions or ...