Topic: probability in php

[nrsh_ram]

Hi there,

I need a help whereby i am wondering if SQL can perform calculation on statistics?

i am looking an sql command to genarate all the sample space ..for an example the user key in 123..
so the sql command muct be able to generate the sample space

{123,132,213,2}

is this can be done in sql?
kindly advice.

[RussellReal]

do you mean.. for 123

123
213
221
132
312
321
231
?

then no

BUT before you insert it into a row you can calculate it yourself..

or when you retrieve it you can calculate it..

[Mchl]

then no

Actually yes... same way you can drive nails into a wall with a screwdriver....

[Gamic]

Just for fun:

Code: [Select]

create table #test(
n int
);
insert into #test(n)
values (1);
insert into #test(n)
values (2);
insert into #test(n)
values (3);

select
distinct convert(char(1),t1.n) + convert(char(1), t2.n) + convert(char(2), t2.n) as 'output'
from #test t1
cross join #test t2
cross join #test t3
order by 1 asc ;
Result:

Code: [Select]

output
------
111
122
133
211
222
233
311
322
333

(9 row(s) affected)

Seemed a lot easier than driving a nail into a wall - but will become a lot more annoying when you need to add extra numbers

[Mchl]

And what these numbers represent?
Where are 123,132,213 as demanded by OP?

Code: [Select]

SELECT
   t1.n,t2.n,t3.n
FROM test AS t1
   CROSS JOIN test AS t2
  ON t1.n != t2.n
   CROSS JOIN test AS t3
  ON t1.n != t3.n AND t2.n != t3.n;


[RussellReal]

Hi there,

I need a help whereby i am wondering if SQL can perform calculation on statistics?

i am looking an sql command to genarate all the sample space ..for an example the user key in 123..
so the sql command muct be able to generate the sample space

{123,132,213,2}

is this can be done in sql?
kindly advice.

however, I'm sure you can define a mysql function for this. but it is so pointless to have mysql do this in the first place, and insert and drop and create tables for each page view.. I shouldn't have said it was impossible, but thats alot more work then just doing it in php..

[Gamic]

Those numbers have gone for a walk .

But yea, just goes to show how silly one little typo can be.

Code: [Select]

create table #test(
n int
);
insert into #test(n)
values (1);
insert into #test(n)
values (2);
insert into #test(n)
values (3);

select
distinct convert(char(1),t1.n) + convert(char(1), t2.n) + convert(char(1), t3.n) as 'output' -- typo last time was t2.n being used twice... silly me!
from #test t1
cross join #test t2
cross join #test t3
order by 1 asc ;

drop table #test;

And this now produces the much better output:

Code: [Select]

output
------
111
112
113
121
122
123 //Here's one!
131
132 //Ah, This one was missing too!
133
211
212
213 //And you!
221
222
223
231
232
233
311
312
313
321
322
323
331
332
333  //Only half evil!


[Mchl]

Yeah. Now we have solutions for both with- and without- repetition permutations. A recursive function in PHP could be written for both.