[Resolved] random

[JehovahsWord]

hi,

how do you get a random link, text, or something of the like? I know how to use rand() to get a random number, but how to you get some sort of random link or something like that. I've looked at some scripts but they all use external files to get the text so it's hard to pull it apart to see what it does to make the random link. thanks for any help

Brandon

[stolzyboy]

what would you like to look like, how many letters, numbers, what kind of words, etc...

[JehovahsWord]

well I"ll tell you exactly what I have.

I have a set of links, which go like this: <a href="file.php?id=1">link text</a>, or whichever id number is there. these ID numbers aren't in order though, but they come out of an auto_increment field in a table, and could go from 1 to 3 to 4 to 7 . . . depending on what previous ones were deleted, etc. so I need to get a random one out of these and display that random link.

Brandon

Originally posted by stolzyboy
what would you like to look like, how many letters, numbers, what kind of words, etc...

[stolzyboy]

well you get all the id's that are available with your query, then you put them into an array, then you use [man]array_rand[/man] to get a random array entry

[JehovahsWord]

ok, so, tell me if this is close to correct?

after connecting to MySQL:

$result = mysql_query("SELECT id FROM config");
$array = array_rand($result);
echo "<a href=\"file.php?id=".$result[$array[0]]."\">link text</a>\n";

I'm just guessing, is it [0] or [1], because in the example on that php page about array_rand, when choosing two entries to show, they used [0] and [1]. so would the code above be right?

Brandon

[stolzyboy]

i would use mysql_fetch_array to gather the results set, then use a for loop to create the array, then use the array_rand after you have that for loop created array, then set that to a variable, then put that in the href

[JehovahsWord]

ok, with that I need a bit of help.

with mysql_fetch_array I usually do while($row = mysql($result)) {
blah
}
do you mean that? or...what, and I'm not sure how to put these into an array. by my thinking I thought $result would be a array since it gathers all the ids in the table, but I noticed that it isn't, because I tried it out. so how do you create the array? a bit of example code if you don't mind? thanks

Brandon

[stolzyboy]

something like this

 
while($row = mysql_fetch_array($result)) 
{ 
for($i=0;$i<mysql_num_fields($result); $i++) 
echo $row[$i] . "<br>"; 
} 

that will give you

$row[0]
$row[1]
$row[2]
$row[3]

up until all the results are grabbed, and they will hold something like

$row[0] will = 2 //whatever id number
$row[1] will = 6 //whatever id number
$row[2] will = 9 //whatever id number
$row[3] will = 10 //whatever id number

[JehovahsWord]

hi,

ok...but that only echos the ids, perfectly well but how do I put that to a variable so I can use array_rand?

Brandon

[stolzyboy]

$row is the array now, so do it on that

[JehovahsWord]

ok, but with the code you gave me, it's just going to print out the rows...like you gave

while ($row = mysql_fetch_array($result)) {
for ($i=0; $i<mysql_num_fields($result); $i++)
echo $row[$i] . "<br>\n";
}
but then how do I add in the array_rand? because that code above is just going to print out somethign like:

1
3
4
8
9

and not have any kind of randomizing affect at all

Brandon

Originally posted by stolzyboy
$row is the array now, so do it on that

[stolzyboy]

don't know why i never thought of this, but this is from mysql.com about rand

You can't use a column with RAND() values in an ORDER BY clause, because ORDER BY would evaluate the column multiple times. From version 3.23 you can do: SELECT FROM table_name ORDER BY RAND() This is useful to get a random sample of a set SELECT FROM table1,table2 WHERE a=b AND c<d ORDER BY RAND() LIMIT 1000. Note that a RAND() in a WHERE clause will be re-evaluated every time the WHERE is executed.

[JehovahsWord]

hi,

1. if you set limit to 1 would it only give you 1 result, then?

2. I got this code which works, also:

   $q = mysql_query('SELECT id FROM config');
   $i = 0;
   while ($row1 = mysql_fetch_array($q, MYSQL_ASSOC))
   {
   $row[$i] = $row1;
   $i++;
   }
   $array = array_rand($row);
   $random = $row[$array];
   echo "<a href=\"file.php?id=".$random['id']."\">".$random['id']."</a>\n";

but always interested, if tha tother way will work as well, the one you just posted.

Originally posted by stolzyboy
don't know why i never thought of this, but this is from mysql.com about rand

[stolzyboy]

yes, if you should use the limit clause and LIMIT 1, that would only give 1 result

[JehovahsWord]

yeah, I tried it out and it works perfectly fine! thanks

[stolzyboy]

np, when you feel this issue is resolved, then mark it so with the link below