I've read about a few alternatives to MySQL's ORDER BY RAND() function, but most of the alternatives apply only to where on a single random result is needed. Does anyone have any idea how to optimize a query that returns multiple random results, such as this: SELECT u.id, p.photo FROM users u, profiles p WHER...
how to form a query to select 'm' rows randomly from a query result which has 'n' rows. for ex; 5 rows from a query result which has 50 rows i try like as follows but it errors select * from (select * from emp where alphabet='A' order by sal desc) order by rand() limit 5; u can wonder that why he needs sub query, i need 5 differen...
Using VB I can create and access a random "cell" in an array like so Dim array(5) as array Dim r as new random r.next(0,5) array(r) will then access a random "cell" based upon r's value. Is there a way to say something like button(r) to directly randomize which button is chosen instead of having to use a random and If's like so? r.n...
How would you set up a program using Java to generate a 5 digit number using the following statement: int n = (int)Math.floor(Math.random()*100000+1) It also has to print the number generated. I have tried writing this different ways and keep coming up with errors. ...
I am having trouble getting rand() to work in C++. rand() normally gives me a very large number. When I try to use the modulo operator (%) to give it a range, it always returns 0, no matter what. Seeding the random number generator at the beginning of the program doesn't help either. ...
Why are my C++ numbers not random? #include <iostream> #include <cstdlib> using namespace std; int main() { int randomNumber = rand() % 100; for (randomNumber = 0; randomNumber < 20; randomNumber++) { cout << randomNumber << endl; } return 0; } //Why are my 20 numbers not random? ...
Does SQLite support seeding the RANDOM() function the same way MySQL does with RAND()? $query = "SELECT * FROM table ORDER BY RAND(" . date('Ymd') . ") LIMIT 1;"; From the MySQL Manual about RAND(N): If a constant integer argument N is specified, it is used as the seed value, which produces a repeatable sequence of column va...
Im just fiddling around with small apps, trying to learn the SDK and ObjC 2. Im trying to display an image randomly and I keep finding different ways up displaying a picture. I have uploaded the picture into the SDKs resources folder. Anyway, here is my code. Can someone steer me in the right direction. #import "randomViewControlle...
Okay... I'm lost (again). How can I make a custom seed for rand() that will keep the pick from the database for a specific period of time: 10 minutes, 1 hours, 1 day, etc. I use this: $query = 'SELECT * FROM table order by rand () LIMIT 1'; To get a random pick every time I refresh the page. I've been reading for days, but I just can...
srand(time(NULL)); for(i = 0; i < n; i++){ for(j = 0; j < (n-1); j++){ a[i][j] = rand(); } } I try to generate random numbers, but they are the same... What should i do? Array declaration: int** a; int i; printf("Enter array size: "); scanf("%d", &n); a = (int**)calloc(n, sizeof(...
I'm using full text search to pull rows. I order the rows based on score (ORDER BY SCORE) , then of the top 20 rows (LIMIT 20), I want to rand (RAND) the result set. So for any specific search term, I want to randomly show 5 of the top 20 results. My workaround is code based- where I put the top 20 into an array then randomly select 5....
int userHP = 100; int enemyHP = rand() % ((userHP - 50) - (userHP - 75)) + 1; okay, for some reason this doesnt seem to work right, im trying to get 50 -25 hp for enemys. also id rather it be a percentage... like int enemyHP = rand() % ((userHP / 50%) - (userHP / 75%)) + 1; but id like to stick with integers and not mess with flo...
first off, is there a such thing as a random access random number generator, where you could not only sequentially generate random numbers as we're all used to, assuming rand100() always generates a value from 0-100: for (int i=0;i<5;i++) print rand100() output: 14 75 36 22 67 but also randomly access any random value like: rand...
So, I'm trying to create a random vector (think geometry, not an expandable array), and every time I call my random vector function I get the same x value, though y and z are different. int main () { srand ( (unsigned)time(NULL)); Vector<double> a; a.randvec(); cout << a << endl; return 0; } using the function //r...
I need to generate a random number. But the twist is that the % of lower numbers should be greater than the higher. For example. rand > 1 to 100 13, 15, 12, 16, 87, 15, 27, 12, 1, 12, 98, 12, 53, 12, 14.... The bold integers will be the ones return from the 1-100 range. The math should be like so rand = a number lower than max/2 ...
Using RAND() in MySQL to get a single random row out of a huge table is very slow: SELECT quote FROM quotes ORDER BY RAND() LIMIT 1 Here is an article about this issue and why this is the case. Their solution is to use two queries: SELECT COUNT(*) AS cnt FROM quotes - Use result to generate a number between 0 and COUNT(*) SELECT q...
Hi How do I select wallpapers randomly, but cache the last selected one for 10 seconds (for performance reasons)? the faster RAND() function use Cache in wallpapers or image i use this but i need to but cache in image timely change after 1 mins or 5 mins to chnage images in RAND() randoms wallpapers i use this : $sql_wallpaper = "S...
How to Cache RAND() random images in PHP MYSQL use to be cache for 5 seconds then on refresh its change images reply ...
I have C++ code that relies heavily on sampling (using rand()), but I want it to be reproducible. So in the beginning, I initialize srand() with a random seed and print that seed out. I want others to be able to run the same code again but initializing srand() with that same seed and get exactly the same answer as I did. But under what ...
I have read that it has something to do with time, also you get from including time.h, so I assumed that much, but how does it work exactly? Also, does it have any tendencies towards odd or even numbers or something like that? And finally is there something with better distribution in the C standard library or the Foundation framework? ...