Undefined Offset in Array PHP (inside a for iteration)

Question

i'm trying to get a group of random rows without repeat any of a BBDD, at the end, the code gies me the questions... but with some errors.... could anyone help me? P.D. the error is in the bolded line. (Undefined offset (in each iteration)) Thanks in advance

mysql_query('SET CHARACTER SET utf8');
$sql=mysql_query("SELECT * FROM Questions");
$num_rows = mysql_num_rows($sql);
$max_value = (int )$num_rows;
$ids[] = array(5);
for ($i = 0; $i < 5; $i++) {
    $repetido = true;

    while($repetido == true){
    $repetido = false;
    $quest_id = rand ( 1, $max_value);//Obtiene el aleatorio

    for ($j = 0; $j < count($ids); $j++) {
        **if ($quest_id == $ids[$i])  $repetido = true;**

    }

    }
    $ids[$i] = $quest_id;
    $sql=mysql_query("SELECT * FROM Questions WHERE id_quest = $quest_id");
    $row = mysql_fetch_array($sql);

    $output[$i]=$row;
}



    echo(json_encode($output));
mysql_close();

more or less :P i'm a student... in witch university only teach Java, SQL and C. ;) — Santanor
– Santanor, Commented Apr 14, 2012 at 16:30

000 · Accepted Answer · 2012-04-14 16:39:07Z

1

$sql = mysql_query("SELECT DISTINCT * FROM Questions ORDER BY RAND() LIMIT 5");
$output = array();
for ($i = 0; $i < 5; $i++) {
    $output[] = mysql_fetch_array($sql);
}

echo(json_encode($output));
mysql_close();

edited Apr 14, 2012 at 16:39

answered Apr 14, 2012 at 16:33

000

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2 Comments

Santanor Over a year ago

and in this code the "question" will NEVER repeat? (i mean... each time i invoke the php, the result will be diferent without any repeated question?)

Santanor Over a year ago

Really dude, thank you so much... now i see why you said that i'm a C programmer. i were making it so difficult. Thnaks!! :)

Bartosz Grzybowski · Accepted Answer · 2012-04-14 16:34:28Z

1

First of all :

$ids[] = array(5);

Doesn't do what You think it does, it just creats array with one element with index 0 and value 5.

If You need just five random rows You can do it easly with MySql:

SELECT * FROM Questions ORDER BY RAND() LIMIT 5;

answered Apr 14, 2012 at 16:34

Bartosz Grzybowski

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Comments

Dmitry Teplyakov · Accepted Answer · 2012-04-14 16:40:33Z

0

After:

$ids[] = array(5);

Add:

var_dump( $ids ); exit;

Use the @joeframbach solution

answered Apr 14, 2012 at 16:40

Dmitry Teplyakov

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