database - category text file to php array with explode -

i need import large category .txt file mysql database. text file has categories 3 levels.

my text file likes example below (+/- 362 entries):

business business = business innovation & ideation = innovation business = economics business = economics = global economics 

my database table structure:

| id | cat | sub_cat | sub_sub_cat |  

what want do, insert categories in database php. separator between cat, sub , sub_sub cat '='. want reach loop insert data database.

thanks in advice.

with kind regards,

nicky

$lines = file('category.txt'); // slurp file , split array lines  foreach($lines $line) {     $parts = explode('=', $line); // decompose line individual sections     $cat = mysql_real_escape_string(trim($parts[0])); // prepare sections sql     $subcat = mysql_real_escape_string(trim($parts[1]));     $subsubcat = mysql_real_escape_string(trim($parts[2]));      $sql = "insert yourtable (cat, sub-cat, sub_sub_cat) values ('$cat', '$subcat', '$subsubcat');";     mysql_query($sql) or die(mysql_error()); }