PHP MySQL查询以奇怪的顺序显示结果

Question

I have two sets of 4 rating inputs in a database table, one with a priority_id of 19 and the other with the priority_id of 20. If I run the sql query below in phpMyAdmin it will return the values for the id primary key field and list them in the right order. If I run my php file and select the values for priority_id 19 they display to the screen in the right order. However, if I select the values for priority_id 20 the id values display to screen in a weird, irrational order. Anyone have ideas what might be causing this? I've tried adding the order by to the sql query but that doesn't seem to help.

$input_ids = array();

$query = "SELECT * FROM rating_inputs WHERE priority_id = '20'";
echo $query . "<br/>";

$result = mysql_query($query);
$z=0;
while($row=mysql_fetch_assoc($result)){
    $input_ids[$z] = $row['id'];
    echo "input id: " . $input_ids[$z] . "<br/>";
    $z=$z+1;
}

These are my database fields and their data. The value field is empty at the moment.

id | priority_id | category_id | value

53 | 19 | 1  |
54 | 19 | 4  |
55 | 19 | 10 | 
56 | 19 | 11 | 
57 | 20 | 1  | 
58 | 20 | 4  | 
59 | 20 | 10 | 
60 | 20 | 11 | 

Answer 1

Records have no intrinsic order in the database. The order in which they're retrieved is random for all intents and purposes. If they are in any particular order, it's because they happened to be stored in that order or were encountered in the index in that order.

If you expect a particular order, use an ORDER BY clause in the query.