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Possible to do a MySQL foreign key to one of two possible tables?
...es (
user_id INT NOT NULL,
place_id INT NOT NULL,
place_type VARCHAR(10) -- either 'states' or 'countries'
-- foreign key is not possible
);
There's no way to model Polymorphic Associations using SQL constraints. A foreign key constraint always references one target table.
Polymorphic As...
Create list of single item repeated N times
...ith n identical elements:
>>> timeit.timeit('itertools.repeat(0, 10)', 'import itertools', number = 1000000)
0.37095273281943264
>>> timeit.timeit('[0] * 10', 'import itertools', number = 1000000)
0.5577236771712819
But wait - it's not a fair test...
>>> itertools.repe...
Creating hidden arguments with Python argparse
...
166
Yes, you can set the help option to add_argument to argparse.SUPPRESS. Here's an example from ...
How do I add a new sourceset to Gradle?
I want to add integration tests to my Gradle build (Version 1.0). They should run separately from my normal tests because they require a webapp to be deployed to localhost (they test that webapp). The tests should be able to use classes defined in my main source set. How do I make this happen?
...
Difference between setUp() and setUpBeforeClass()
...ce constructed and the following methods called on it)
setUp()
test1()
tearDown()
(Test class second instance constructed and the following methods called on it)
setUp()
test2()
tearDown()
(Test class third instance constructed and the following methods called on it)
...
ggplot with 2 y axes on each side and different scales
...
15 Answers
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In Python, using argparse, allow only positive integers
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251
This should be possible utilizing type. You'll still need to define an actual method that decide...
Why can't I overload constructors in PHP?
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14 Answers
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Does Qt support virtual pure slots?
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164
Yes, just like regular c++ pure virtual methods. The code generated by MOC does call the pure ...