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How to concatenate columns in a Postgres SELECT?
...n any case.
For non-string data types, you can "fix" the 1st statement by casting at least one argument to text. (Any type can be cast to text):
SELECT a::text || b AS ab FROM foo;
Judging from your own answer, "does not work" was supposed to mean "returns NULL". The result of anything concatena...
How to get hosting Activity from a view?
...
This is a pretty dangerous cast to make. There is a good chance (if you're using appcompat) that the context you've got is wrapped, casting something like a ContextThemeWrapper to Activity will throw a ClassCastException. You'd need a way to unwrap the...
Covariance and contravariance real world example
...);
Covariant(fruit);
Covariant(apple); //apple is being upcasted to fruit, without the out keyword this will not compile
}
public void Contravariance()
{
IContravariant<Fruit> fruit = new Contravariant<Fruit>();
IContravariant<Apple> ap...
How to turn on (literally) ALL of GCC's warnings?
...-bounds -Warray-temporaries -Wassign-intercept -Wattributes -Wbad-function-cast -Wbool-compare -Wbuiltin-macro-redefined -Wc++-compat -Wc++0x-compat -Wc++14-compat -Wc-binding-type -Wc90-c99-compat -Wc99-c11-compat -Wcast-align -Wcast-qual -Wchar-subscripts -Wcharacter-truncation -Wchkp -Wclobbered ...
NSLog/printf specifier for NSInteger?
...
The official recommended approach is to use %ld as your specifier, and to cast the actual argument to a long.
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SQL “between” not inclusive
...t when the day starts.
One way to fix this is:
SELECT *
FROM Cases
WHERE cast(created_at as date) BETWEEN '2013-05-01' AND '2013-05-01'
Another way to fix it is with explicit binary comparisons
SELECT *
FROM Cases
WHERE created_at >= '2013-05-01' AND created_at < '2013-05-02'
Aaron Bert...
Why does the is operator return false when given null?
... conditions
are met:
expression is not null.
expression can be cast to type. That is, a cast expression of the
form (type (expression) will complete without throwing an exception.
For more information, see 7.6.6 Cast expressions.
...
Splitting string into multiple rows in Oracle
...error, '[^,]+', 1, levels.column_value)) as error
from
temp t,
table(cast(multiset(select level from dual connect by level <= length (regexp_replace(t.error, '[^,]+')) + 1) as sys.OdciNumberList)) levels
order by name
EDIT:
Here is a simple (as in, "not in depth") explanation of the que...
What is the point of noreturn?
...unit or top. Its logical equivalent is True. Any value can be legitimately cast to void (every type is a subtype of void). Think about it as "universe" set; there are no operations in common to all the values in the world, so there are no valid operations on a value of type void. Put it another way,...
In SQL, how can you “group by” in ranges?
... Server the simplest statement is as follows:
SELECT
[score range] = CAST((Score/10)*10 AS VARCHAR) + ' - ' + CAST((Score/10)*10+9 AS VARCHAR),
[number of occurrences] = COUNT(*)
FROM #Scores
GROUP BY Score/10
ORDER BY Score/10
This assumes a #Scores temporary table I used to test it, I...