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Do I need elements in persistence.xml?
... <jar-file>MyOrderApp.jar</jar-file>
<class>com.widgets.Order</class>
<class>com.widgets.Customer</class>
</persistence-unit>
</persistence>
This file defines a persistence unit
named OrderManagement, which uses a
JTA-aware d...
How can I tell when a MySQL table was last updated?
...
For details including InnoDB limitations see dev.mysql.com/doc/refman/5.5/en/show-table-status.html (show table status uses information_schema.tables)
– KCD
May 9 '12 at 21:12
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What's the deal with a leading underscore in PHP class methods?
... of OO was pretty bad, and didn't include things like private methods. To compensate, PHP developers prefaced methods that were intended to be private with an underscore. In some older classes you'll see /**private*/ __foo() { to give it some extra weight.
I've never heard of developers prefacing...
What are the mechanics of short string optimization in libc++?
...It is a different ABI, and if accidentally mixed with a libc++ std::string compiled with a different setting of _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT will create run time errors.
I recommend this flag only be changed by a vendor of libc++.
...
Easiest way to rename a model using Django/South?
...question, the simple model/table rename is pretty straightforward. Run the command:
./manage.py schemamigration yourapp rename_foo_to_bar --empty
(Update 2: try --auto instead of --empty to avoid the warning below. Thanks to @KFB for the tip.)
If you're using an older version of south, you'll n...
Git: what is a dangling commit/blob and where do they come from?
I'm looking for the basic info on dangling commits & blobs.
4 Answers
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NullPointerException accessing views in onCreate()
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Is there documentation for the Rails column types?
...(names, emails, etc)
Text:
Unlimited length (depending on DBMS)
Use for comments, blog posts, etc. General rule of thumb: if it's captured via textarea, use Text. For input using textfields, use string.
Integer:
Whole numbers
Float:
Decimal numbers stored with floating point precision
Preci...
Is there an easy way to check the .NET Framework version?
... }
}
}
...
// Checking the version using >= will enable forward compatibility,
// however you should always compile your code on newer versions of
// the framework to ensure your app works the same.
private static string CheckFor45DotVersion(int releaseKey)
{
if (releaseKey >= ...
What's the point of map in Haskell, when there is fmap?
...
I would like to make an answer to draw attention to augustss's comment:
That's not actually how it happens. What happened was that the type of map was generalized to cover Functor in Haskell 1.3. I.e., in Haskell 1.3 fmap was called map. This change was then reverted in Haskell 1.4 a...