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Difference between Django's annotate and aggregate methods?
Django's QuerySet has two methods, annotate and aggregate . The documentation says that:
3 Answers
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Ruby Metaprogramming: dynamic instance variable names
...hash.each {|k,v| instance_variable_set("@#{k}",v)}
– Andrei
Jun 10 '12 at 20:32
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Android image caching
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And now the punchline: use the system cache.
URL url = new URL(strUrl);
URLConnection connection = url.openConnection();
connection.setUseCaches(true);
Object response = connection.getContent();
if (response instanceof Bitma...
Please explain about insertable=false and updatable=false in reference to the JPA @Column annotation
...ted entity in question isn't in the current entity. E.g. you have a Person and an Address. You'd like to add insertable=false, updatable=false to the @OneToMany relationship with the Person entity in the Address entity, simply because it's not the responsibility of the Address entity to create or up...
How to detect the swipe left or Right in Android?
I have an EditText view in android. On this I want to detect swipe left or right. I am able to get it on an empty space using the code below. But this does not work when I swipe on an EditText . How do I do that? Please let me know If I am doing something wrong. Thank you.
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Why are properties without a setter not serialized
I have a serializable class and one of the properties in my class generates a Guid in the getter. The property implements no setter and is ignores during serialization. Why is that and do I always have to implement a setter in order for my property to be serialized.
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Hibernate problem - “Use of @OneToMany or @ManyToMany targeting an unmapped class”
I'm finding my feet with Hibernate Annotations and I've hit a problem I hope someone can help with.
7 Answers
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Is it possible for a computer to “learn” a regular expression by user-provided examples?
...ton, it is possible to learn some regular expressions by a program. Kearns and Valiant show some cases where it is not possible to learn a finite automaton. A related problem is learning hidden Markov Models, which are probabilistic automata that can describe a character sequence. Note that most mod...
Template default arguments
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@OlafDietsche but you can't have a template class and a non-template class with the same name, so the compiler should be able to decide by just looking at what the name is.
– Seth Carnegie
Mar 12 '13 at 23:13
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Most efficient way to check for DBNull and then assign to a variable?
...to avoid. By writing row.IsNull(columnName) you're reading it once already and reading it again. Not saying that will make a difference, but theoretically it can be less efficient..
– nawfal
Feb 6 '13 at 16:31
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