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Select between two dates with Django
I am looking to make a query that selects between dates with Django.
4 Answers
4
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Best way to check for “empty or null value”
... '
Demo
Empty string equals any string of spaces when cast to char(n):
SELECT ''::char(5) = ''::char(5) AS eq1
, ''::char(5) = ' '::char(5) AS eq2
, ''::char(5) = ' '::char(5) AS eq3;
Result:
eq1 | eq2 | eq3
----+-----+----
t | t | t
Test for "null or empty string" w...
How to handle click event in Button Column in Datagridview?
...ast the sender to type DataGridView, we can get the Columns collection and select the current column using e.ColumnIndex. Then check if that object is of type DataGridViewButtonColumn.
Of course, if you need to distinguish between multiple buttons per grid, you can then select based on the column n...
Setting Short Value Java
...or byte or short types. Instead, you may declare it as such using explicit casting:
byte foo = (byte)0;
short bar = (short)0;
In your setLongValue(100L) method call, you don't have to necessarily include the L suffix because in this case the int literal is automatically widened to a long. This is...
How to check that an object is empty in PHP?
...
You can cast to an array and then check if it is empty or not
$arr = (array)$obj;
if (!$arr) {
// do stuff
}
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What does “dereferencing” a pointer mean?
...he pointer may be relative to some specific memory area, which the CPU may select based on CPU "segment" registers or some manner of segment id encoded in the bit-pattern, and/or looking in different places depending on the machine code instructions using the address.
For example, an int* properly ...
Find index of a value in an array
... return -1;
}
And you can use LINQ as well:
int keyIndex = words
.Select((v, i) => new {Word = v, Index = i})
.FirstOrDefault(x => x.Word.IsKey)?.Index ?? -1;
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How do I make the method return type generic?
...nimal> T callFriend(String name, Class<T> type) {
return type.cast(friends.get(name));
}
Then call it as such:
jerry.callFriend("spike", Dog.class).bark();
jerry.callFriend("quacker", Duck.class).quack();
This code has the benefit of not generating any compiler warnings. Of course ...
Is it possible to print a variable's type in standard C++?
...ecltype((ci))>() << '\n';
std::cout << "decltype(static_cast<int&>(i)) is " << type_name<decltype(static_cast<int&>(i))>() << '\n';
std::cout << "decltype(static_cast<int&&>(i)) is " << type_name<decltype(stati...
How do I convert a decimal to an int in C#?
...an also use Decimal.ToInt32. Again, see MSDN. Finally, you can do a direct cast as in
decimal value = 3.14m;
int n = (int) value;
which uses the explicit cast operator. See MSDN.
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