Create Mysql Records From a Comma separated Values String

Hi to everyone i have the following problem i have a string $foo which contains (n variable) comma separated values (example "1,17,23,45") and i want to insert these values in a mysql table . The destination field is int type and i need to insert one record per value Do you know which php function(s) should i use in order to (loop -extract the values from string) and do that ?? Thanks in advance for your help regars simos