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SQL query return data from multiple tables
... Joins (this stackOverflow answer is excellent to describe types of joins)
Intersect queries (and how to reproduce them if your database doesn't support them) - this is a function of SQL-Server (see info) and part of the reason I wrote this whole thing in the first place.
Part 2
Subqueries - what...
Resolve build errors due to circular dependency amongst classes
...e: B.h
class B {
A _a;
};
// file main.cc
#include "A.h"
#include "B.h"
int main(...) {
A a;
}
When you are compiling the .cc file (remember that the .cc and not the .h is the unit of compilation), you need to allocate space for object A. So, well, how much space then? Enough to store B! What...
Difference Between Invoke and DynamicInvoke
... is very fast - everything is already pre-validated. For example:
Func<int,int> twice = x => x * 2;
int i = 3;
int j = twice.Invoke(i);
// or just:
int j = twice(i);
However! If you just know that it is Delegate, it has to resolve the parameters etc manually - this might involve unboxing...
Check if a string contains a string in C++
... std::cout << "found!" << '\n';
}
Note: "found!" will be printed if s2 is a substring of s1, both s1 and s2 are of type std::string.
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Log to the base 2 in python
...n_or_method'>
String Form: <built-in function log>
Namespace: Interactive
Docstring:
log(x[, base]) -> the logarithm of x to the given base.
If the base not specified, returns the natural logarithm (base e) of x.
In [25]: math.log(8,2)
Out[25]: 3.0
...
How to Parse Command Line Arguments in C++? [duplicate]
...
introducing boost to a code base just to parse command line options is a bit "sledgehammer to crack a nut". If boost is there already use it. Otherwise have a look at something like gopt. Nothing against boost in general but ...
Why should we typedef a struct so often in C?
...ce it provides a smidgen more abstraction.
Stuff like
typedef struct {
int x, y;
} Point;
Point point_new(int x, int y)
{
Point a;
a.x = x;
a.y = y;
return a;
}
becomes cleaner when you don't need to see the "struct" keyword all over the place, it looks more as if there really is a ty...
Good way of getting the user's location in Android
...nupdate is considered 'old' if its older than the configured
// update interval. this means, we didn't get a
// update from this provider since the last check
long old = System.currentTimeMillis() - getGPSCheckMilliSecsFromPrefs();
boolean gpsIsOld = (gpslocation.getTime() < old);...
Android: Access child views from a ListView
...nd combine with part of Feet's answer above, can give you something like:
int wantedPosition = 10; // Whatever position you're looking for
int firstPosition = listView.getFirstVisiblePosition() - listView.getHeaderViewsCount(); // This is the same as child #0
int wantedChild = wantedPosition - firs...
Make a negative number positive
...
Just call Math.abs. For example:
int x = Math.abs(-5);
Which will set x to 5.
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