HELP.. XOR in mysql..

[Emir Bukvic]

here is the deal...

is there XOR function in MySql??? This is what i have to do... i retreive a phone number and number of seconds from one table... then i need to compare the phone number to a list of country codes and sub codes (for cities or mobile phones) in another table.. so... if the phone number matches both contry code and sub code, i will get the price of the call by multiplying the number of seconds by the tariff that matches country and sub code... if the phone number doesn't match the country and sub code, i want to check if it matches only the country code.. if it does, then i use a different tariff to calculate the price of the call.... however, if the first condition is true, obviously the second condition is true as well... so what can i do to eliminate the second condition if the first one is true?? i know AND and OR operators can't help me... does anyone know what to do???

thanx in advance