插入时变量的值不同

Question

I want to generate a pair of random numbers 1234567890-9876543210 (10 digits each) I made this code. It works fine it generates a pair of random numbers BUT if I try to insert it into database I get same results multiple times. Let's say I get 1234567890 more than once. If I echo the insert statement I get different results but when I want to query it into database I get same results.

$numbers = array(0,1,2,3,4,5,6,7,8,9);
srand(time());
$f = fopen('sql0.txt', 'w');

for($i=0;$i<100000;$i++)
{

   $r = NULL;
   $r2 = NULL;

   for($x=0;$x<10;$x++)
   {
       $n = rand(0,9);
       $r .= $numbers[$n];
    }

    for($x=0;$x<10;$x++)
    {
       $n1 = rand(0,9);
       $r2 .= $numbers[$n1];
    }

    echo("INSERT INTO ci_codes VALUES (NULL, '$r', '$r2', '0')<br>");

}

Answer 1

Do you need the INSERT expression inside your loop? That might cause the trouble.

As others have mentioned, it is better to just generate the numbers once with the php function, then run your MySql Query.

$r = mt_rand(0, 10000000);
$r2 = mt_rand(0, 10000000);

echo("INSERT INTO ci_codes VALUES (NULL, '$r', '$r2', '0'");