Notice: Undefined offset: 0, PHP/MySQL

Question

I'm very new to PHP/MySQL however i believe the code "should" work.

Undefined offset: 0 on line 59 I'm unsure why this error is occurring. Wouldn't count array > 0 prevent the undefined?

$result = mysql_query("select InterestID FROM userinterest WHERE MemberID ='$MemberID'");

$result_array = array();
$result_array2 = array();
$i=0;

while($row=mysql_fetch_array($result)){
$result_array[$i] = $row['InterestID'];
$i++;
}
$results;

for($ID=100; $ID<400; $ID++){

for($XI=0; $XI<4; $XI++){

for($X=0; $X<4; $X++){

$result2 = mysql_query("select InterestID FROM userinterest WHERE MemberID ='$ID'");

while($row2=mysql_fetch_array($result2)){
$result_array2[$i] = $row2['InterestID'];
$i++;
}

if ((count($result_array2[$X]) > 0)) {
if($result_array2[$X] == $result_array[$XI])
{
$match++;
}

}

}   
}

if($match>0){mysql_query("INSERT INTO matchtemp(MemberID, Count)VALUES ('$ID','$match')");
}
$match=0;
}

Answer 1

Why are you doing this?

while($row=mysql_fetch_array($result)){
$result_array[$i] = $row['InterestID'];
$i++;
}

Every time you push an element into an array, its automatically indexed. Try:

while($row = mysql_fetch_array($result)){
$result_array[] = $row['InterestID'];
}