Hi Dr. Sun,

I'm wondering on whether there should be a relationship between Accident and Person, since it says that the insurrance company needs to know the Person and Car that is involved in an accident.. However, I thought that since there's a relationship between Person and Car, and if there's a relationship between Car and Accident, then we can find Person has the Car that is involved in the Accident.. Therefore, we don't need a relationship between the Person and the Accident..??

Thanks,

Ok, but I'm thinking on whether we need the car and driver name as an immediate information? Such that if I just query the Accident table:

SELECT * FROM Accident WHERE date = now();

I have both the car and driver name that is involved in the accident.. Another way is to join tables..

cysun wrote:

HelloWorld wrote:

Ok, but I'm thinking on whether we need the car and driver name as an immediate information? Such that if I just query the Accident table:

SELECT * FROM Accident WHERE date = now();

I have both the car and driver name that is involved in the accident.. Another way is to join tables..

If "immediate information" means being attributes of the Accident entity set, the answer is no.

And BTW, you won't get anything if you do "WHERE date = now()".

Thanks! yeah, I just made that up..