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When should I use cross apply over inner join?
...APPLY works better on things that have no simple JOIN condition.
This one selects 3 last records from t2 for each record from t1:
SELECT t1.*, t2o.*
FROM t1
CROSS APPLY
(
SELECT TOP 3 *
FROM t2
WHERE t2.t1_id = t1.id
ORDER BY
t2.ran...
What is the “N+1 selects problem” in ORM (Object-Relational Mapping)?
The "N+1 selects problem" is generally stated as a problem in Object-Relational mapping (ORM) discussions, and I understand that it has something to do with having to make a lot of database queries for something that seems simple in the object world.
...
Can I call memcpy() and memmove() with “number of bytes” set to zero?
...values, as described in 7.1.4. On such a call, a
function that locates a character finds no occurrence, a function that compares two
character sequences returns zero, and a function that copies characters copies zero
characters.
So the answer is no; the check is not necessary (or yes; you ca...
Can I use a binary literal in C or C++?
...namespace std;
int main() {
unsigned short b = BOOST_BINARY( 10010 );
char buf[sizeof(b)*8+1];
printf("hex: %04x, dec: %u, oct: %06o, bin: %16s\n", b, b, b, itoa(b, buf, 2));
cout << setfill('0') <<
"hex: " << hex << setw(4) << b << ", " <<
...
What is a higher kinded type in Scala?
...va 5 generics are first-order.
The first-order interpretation of the above characterizations of abstractions are:
A type constructor is a type that you can apply to proper type arguments to "construct" a proper type.
A value constructor is a value that you can apply to proper value arguments to "co...
Get value when selected ng-option changes
...ple:
<div ng-app="App" >
<div ng-controller="ctrl">
<select ng-model="blisterPackTemplateSelected" ng-change="changedValue(blisterPackTemplateSelected)"
data-ng-options="blisterPackTemplate as blisterPackTemplate.name for blisterPackTemplate in blisterPackTemplates...
C/C++ Struct vs Class
...bjects. X AVOID defining a struct unless the type has all of the following characteristics: 1. It logically represents a single value, similar to primitive types (int, double, etc.). 2. It has an instance size under 16 bytes. 3. It is immutable.
– Abhijeet
De...
Javascript seconds to minutes and seconds
... ... modify (9<s?':':':0') to (10>s?':0':':') (adding 1 char but 'sacrificing' 5 out of 6 true-paths to false-paths) OR (10<=s?':':':0') (adding 2 chars but maintaining 5 out of 6 true paths). Then I advise to change that final trailing +s to +(s|0) instead of Math.floor(s), as...
How to reset postgres' primary key sequence when it falls out of sync?
...
-- Login to psql and run the following
-- What is the result?
SELECT MAX(id) FROM your_table;
-- Then run...
-- This should be higher than the last result.
SELECT nextval('your_table_id_seq');
-- If it's not higher... run this set the sequence last to your highest id.
-- (wise to run...
Typedef function pointer?
...ld use the original type, for instance
typedef int myinteger;
typedef char *mystring;
typedef void (*myfunc)();
using them like
myinteger i; // is equivalent to int i;
mystring s; // is the same as char *s;
myfunc f; // compile equally as void (*f)();
As you can ...