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Best practices for in-app database migration for Sqlite
...
I maintain an application that periodically needs to update a sqlite database and migrate old databases to the new schema and here's what I do:
For tracking the database version, I use the built in user-version variable that sqlite provides (sqlite does nothing w...
Unique constraint on multiple columns
...ied from technet's documentation, is in the form of:
CONSTRAINT constraint_name UNIQUE [ CLUSTERED | NONCLUSTERED ]
(
column [ ASC | DESC ] [ ,...n ]
)
Therefore, the resuting table definition would be:
CREATE TABLE [dbo].[user](
[userID] [int] IDENTITY(1,1) NOT NULL,
[fcode] [int] ...
Why is Go so slow (compared to Java)?
...n spends runtime supporting language features that the benchmark doesn't really need. In most compiled languages a sufficiently clever compiler could in theory strip out what isn't needed, but there comes a point where you're rigging the demo, since very few real users of the language would write pr...
Does Python have “private” variables in classes?
...ass variables. In Java, nothing prevents you from doing the same if you really want to - after all, you can always edit the source of the class itself to achieve the same effect. Python drops that pretence of security and encourages programmers to be responsible. In practice, this works very nicely...
Eclipse, regular expression search and replace
...\))
replace: ((TypeName)$1)
Hint: CTRL + Space in the textboxes gives you all kinds of suggestions for regular expression writing.
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How to check if all of the following items are in a list?
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Operators like <= in Python are generally not overriden to mean something significantly different than "less than or equal to". It's unusual for the standard library does this--it smells like legacy API to me.
Use the equivalent and more clearly-named method, ...
Invert “if” statement to reduce nesting
...cked this code from the refactoring catalog. This specific refactoring is called: Replace Nested Conditional with Guard Clauses.
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g++ undefined reference to typeinfo
...ill contain null-pointer most likely). However, nobody prohibits you from calling this pure virtual function in a non-virtual manner, i.e. by using a fully-qualified name. In this case the linker will look for the body, and you will have to define the function. And yes, you can define a body for a p...
C++ performance challenge: integer to std::string conversion
... val /= 10;
}
return s;
}
This will blow up on systems that disallow unaligned memory accesses (in which case, the first unaligned assignment via *(short*) would cause a segfault), but should work very nicely otherwise.
One important thing to do is to minimize the use of std::string. (I...
PHP foreach change original array values
...lt;= 0) {
$fields[$key]['value'] = "Some error";
}
}
So basically use $field when you need the values, and $fields[$key] when you need to change the data.
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