If there are three tables to choose from -
Sailors(sid,sname); Reserves(sid,bid); Boats(bid,color)
Question is to choose a sailor who reserved a red boat.
My question is what is the difference between these two TRC expressions.
Which of the above is correct? Are both correct? Are none correct?
can you explain how number of comparisons in first query will be less?
Refund time depends on the payment mode --...