mysql "offset 0 is invalid" error

[bliss322]

hi.

i've got a checkbox list that gets populated by previous selections.

the problem is, if no options were selected previously, i'm getting an "offset 0 is invalid for mysql result index error"

i'm checking to see if the sql array has data, yet i'm still getting an error?

suggestions?

code sample:

//this is the second query
$query2="Select $dd2 from ".$dd."list where property_id=$id";
$results2 = mysql_query($query2);

//this is going through the first array
while($values = mysql_fetch_array($results)){

           //checks to see if results2 is valid
           //this is where it's giving the error
if ($results2) {
    while($values2 = mysql_fetch_array($results2)){
        if ($values2[$dd2] == $values[ID]) {
					          $checked = "checked";
                      }	
      }
				mysql_data_seek($results2,0);
}

echo "<input type='checkbox' name='".$dd2."[]' value=\"$values[ID]\" ".$checked.">$values[Name]<br />";
$checked = "";

};

[rubric]

Originally posted by bliss322

if ($results2) {
while($values2 = mysql_fetch_array($results2)){
if ($values2[$dd2] == $values[ID]) {
$checked = "checked";
}
}
mysql_data_seek($results2,0);
}

This is what's causing the error. You have a while statement that loops until all rows are used. You cannot go back and see what the results were after you've advanced the pointer. In a situation like this, you should grab all the information from $results2 and store them in an array. This way, you can always go back and get the info from the array. Does this make sense?

I've never used the mysql_data_seek() function so I could be completely wrong.

Rubric

[bliss322]

mysql_data_seek($results2,0) is equivalent to the reset() function only for a mysql_fetch_array.

so, it's supposed to do what you've just described and it does that. if there is a value to the array, then, after the while statement, it resets the array to the beginning for the next round.

the problem is when there is no data in the array. that's when i get teh error. I THOUGHT by wrapping it all with a

if ($results2) {
...
}

any empty arrays would skip over but that's not happening. how can i code it to skip over those statements if there's no value to the array?