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Possible to do a MySQL foreign key to one of two possible tables?
...s (
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 Ass...
What Android tools and methods work best to find memory/resource leaks? [closed]
...
90
One of the most common errors that I found developing Android Apps is the “java.lang.OutOfMemo...
What are the differences between “=” and “
...gnment. For instance, the following performs assignment:
median((x = 1 : 10))
But also:
if (! (nf = length(from))) return()
Now you might object that such code is atrocious (and you may be right). But I took this code from the base::file.copy function (replacing <- with =) — it’s a per...
What is memoization and how can I use it in Python?
... |
edited Apr 8 '18 at 0:06
Richard
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ans...
How to define static property in TypeScript interface
...interface Date {
MinValue: Date;
}
Date.prototype.MinValue = new Date(0);
Called using:
var x = new Date();
console.log(x.MinValue);
And if you want to make it available without an instance, you also can... but it is a bit fussy.
interface DateStatic extends Date {
MinValue: Date;
}
...
Click Event on UIImageView programmatically in ios
...ding Thanks
– Ravi
Nov 25 '17 at 14:06
'let singleTap = UITapGestureRecognizer(target: self, action: #selector(Navigat...
JavaScript Nested function
...
140
Functions are another type of variable in JavaScript (with some nuances of course). Creating a f...
FileNotFoundException while getting the InputStream object from HttpURLConnection
...alusC
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Purpose of Activator.CreateInstance with example?
...Instance("MyAssembly", ClassName))
and can then do stuff like:
obj.A = 100;
That's its purpose. It also has many other overloads such as providing a Type instead of the class name in a string. Why you would have a problem like that is a different story. Here's some people who needed it:
Creat...