echo random id numbers from mysql database without repeating numbers?

How do I echo random id numbers from mysql database without repeating numbers?

this is my sample code:

$query = mysql_query("SELECT * FROM store"); 
$number=mysql_num_rows($query); 

for ($count=1; $count<= $number ; $count++)
{

  $id = mysql_query ("SELECT id FROM store ORDER BY RAND() LIMIT $number");
  $id = mysql_fetch_assoc($id);
  $id = $id['id'];

  echo $id;

}

It will echo six random numbers but have instances like "1 1 3 2 4 5" where 1 is echoed开发者_如何学运维 twice instead of once. thanks in advance

---

Just order your results by rand and limit their number, your id has to be unique :

SELECT * FROM store ORDER BY RAND() LIMIT 0,6

---

The Problem is, that you do a SELECT inside of the loop, instead of selecting once and loop over the result.

$query = mysql_query("SELECT * FROM store"); 
$number=mysql_num_rows($query); 

$result = mysql_query ("SELECT id FROM store ORDER BY RAND() LIMIT $number");
while ($row = mysql_fetch_assoc($result)) {
    echo $row["id"];
}

BTW: SELECT * to get the number of recordsets is ugly, use SELECT count(id)instead

---

If you're coming out of php you're probably better off (faster, easier, no locking issues) to randomize your numbers there. And SQL queries inside loops is an antipattern.