complicated transtable problem

Hi there, I am still struggling with following problem: There are two tables in mysql 1. city fields: ID, countryid, provinceid, city containing 2.5 million entries. 2. province fields: ID, countryid, provinceid, provincename Now there are some cities without a valid province id in the other table. Means that those city do not find the right province name. I would like to: 1. delete those province rows (all belonging to this country) in the province table 2. set the province_id to "" in the city table. Seems to be complicated.. maybe someone could give me a hint on this Thanx, Andy