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Possible to do a MySQL foreign key to one of two possible tables?
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What you're describing is called Polymorphic Associations. That is, the "foreign key" column contains an id value that must exist in one of a set of target tables. Typically the target tables are related in some way, such as being instances of some c...
How does the vim “write with sudo” trick work?
Many of you have probably seen the command that allows you to write on a file that needs root permission, even when you forgot to open vim with sudo:
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What is pseudopolynomial time? How does it differ from polynomial time?
...ng TSP takes time O(n · n!), which isn't polynomial time.
These runtimes all refer to some variable n that tracks the size of the input. For example, in selection sort, n refers to the number of elements in the array, while in TSP n refers to the number of nodes in the graph. In order to standardi...
How to remove not null constraint in sql server using query
... NULL
– Adam Butler
Jun 28 '11 at 1:16
or you can do : alter table table_name modify column_name type(30) NULL. 30 bei...
AngularJS - How can I reference the property name within an ng-Repeat
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answered Oct 29 '12 at 16:04
darkyndydarkyndy
57755 silver badges1515 bronze badges
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Laravel 4: how to “order by” using Eloquent ORM [duplicate]
...till works in 5.1
– Geoherna
Dec 7 '16 at 18:50
4
Absolutely still working in 5.4
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How to auto-generate a C# class file from a JSON string [closed]
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Shaun LuttinShaun Luttin
97.8k6161 gold badges310310 silver badges385385 bronze badges
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如何实现for循环？？ - App应用开发 - 清泛IT社区，为创新赋能！
int main() { uint32_t val = 1; for (uint8_t i = 1; i <= 4; i++) { val *= 16; // 下一次就是 16^1, 16^2, ... } return 0;}这段程序，如何用代码块实现？？
convert double to int
....Math.Floor(dblVal));
– kris
May 1 '16 at 8:07
9
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What does the explicit keyword mean?
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The compiler is allowed to make one implicit conversion to resolve the parameters to a function. What this means is that the compiler can use constructors callable with a single parameter to convert from one type to another in order to get t...