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What is a Manifest in Scala and when do you need it?
...a workaround for Java's type erasure. But how does Manifest work exactly and why / when do you need to use it?
4 Answers
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Select first row in each GROUP BY group?
... BY p.customer) y ON y.customer = x.customer
AND y.max_total = x.total
GROUP BY x.customer, x.total
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Design Patterns: Factory vs Factory method vs Abstract Factory
...uctor".
Let's say you want to be able to create two kinds of Fruit: Apple and Orange.
Factory
Factory is "fixed", in that you have just one implementation with no subclassing. In this case, you will have a class like this:
class FruitFactory {
public Apple makeApple() {
// Code for creati...
How to align input forms in HTML
I'm new to HTML and I'm trying to learn how to use forms.
16 Answers
16
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How to do an update + join in PostgreSQL?
... -- joined table
WHERE
a.abiturient_id = b.id AND -- JOIN ON clause
a.documents_taken_at::date < b.certificate_issued_at -- Subquery WHERE
As you can see, original subquery JOIN's ON clause have become one of WHERE conditions, which is ...
Why does calling a method in my derived class call the base class method?
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There's a difference between new and virtual/override.
You can imagine, that a class, when instantiated, is nothing more than a table of pointers, pointing to the actual implementation of its methods. The following image should visualize this pretty well:
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What is the $? (dollar question mark) variable in shell scripting? [duplicate]
I'm trying to learn shell scripting, and I need to understand someone else's code. What is the $? variable hold? I can't Google search the answer because they block punctuation characters.
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Admob Error in Eclipse for android:configChanges
Eclipse is giving me an error on the android:configChanges line in my AndroidManifest.xml:
7 Answers
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How to open every file in a folder?
...have a python script parse.py, which in the script open a file, say file1, and then do something maybe print out the total number of characters.
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The Role Manager feature has not been enabled
...s from code instead of web.config? I tried putting it in Application_Start and it says This method can only be called during the application's pre-start initialization phase.
– Maslow
May 8 '13 at 15:17
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