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SQL ON DELETE CASCADE, Which Way Does the Deletion Occur?
...have CourseID on table Category?
Maybe you should restructure your schema into this,
CREATE TABLE Categories
(
Code CHAR(4) NOT NULL PRIMARY KEY,
CategoryName VARCHAR(63) NOT NULL UNIQUE
);
CREATE TABLE Courses
(
CourseID INT NOT NULL PRIMARY KEY,
BookID INT NOT NULL,
CatCode CHAR(4) ...
Shorthand way for assigning a single field in a record, while copying the rest of the fields?
... updating record fields. In GHCi you can do --
> data Foo = Foo { a :: Int, b :: Int, c :: String } -- define a Foo
> let foo = Foo { a = 1, b = 2, c = "Hello" } -- create a Foo
> let updateFoo x = x { c = "Goodbye" } -- function to update Foos
> updateFoo foo ...
How does '20 seconds' work in Scala?
...0.seconds()*.
Second, an "implicit conversion" is applied. Since 20 is an Int and Int has no seconds method, the compiler searches for an implicit conversion that takes an Int and returns something that does have a seconds method, with the search constrained by the scope of your method call.
You h...
Check whether number is even or odd
...
You can use the modulus operator, but that can be slow. If it's an integer, you can do:
if ( (x & 1) == 0 ) { even... } else { odd... }
This is because the low bit will always be set on an odd number.
share
...
Do you need to dispose of objects and set them to null?
...s Dispose() needs to implement any logic? Does it have to do something? Or internally when Dispose() is called signals GC that is good to go? I checked the source code for the TextWriter for example and Dispose has no implementation.
– Mihail Georgescu
Jan 27...
Checking if an Android application is running in the background
...e decision about what the "next" activity to go to is always done at the point where the switch is to happen, and it is not until that exact point (where the activity state is briefly locked down to do the switch) that we actually know for sure what the next thing will be.
And the implementatio...
Difference between Math.Floor() and Math.Truncate()
... Here's the reference.
For completeness, Math.Round rounds to the nearest integer. If the number is exactly midway between two integers, then it rounds towards the even one. Reference.
See also: Pax Diablo's answer. Highly recommended!
...
Strip Leading and Trailing Spaces From Java String
...his string, with all leading
* and trailing {@link Character#isWhitespace(int) white space}
* removed.
* <p>
* If this {@code String} object represents an empty string,
* or if all code points in this string are
* {@link Character#isWhitespace(int) white space}, then an empty string
* i...
TextView.setTextSize behaves abnormally - How to set text size of textview dynamically for different
...
The difference here is that in the setTextSize(int size) method, the unit type by default is "sp" or "scaled pixels". This value will be a different pixel dimension for each screen density (ldpi, mdpi, hdpi).
getTextSize(), on the other hand, returns the actual pixel di...
What happens if I define a 0-size array in C/C++?
Just curious, what actually happens if I define a zero-length array int array[0]; in code? GCC doesn't complain at all.
7...