SWIMMER(SSN, SNAME, LEVEL)
BEACH(B#, BNAME, STATE, POLLUTION)
SWIMMING(SSN, B#, DATE, DURATION)
The first relation indicates the swimmers and their level (beginner, intermediate, advanced) the second indicates different beaches across the country. Each beach has a number (B#) a name (BNAME) and a pollution rate of 0 (low pollution), 1 (moderate pollution) or 2 (high pollution). The third records the members swimming.
Express the following queries in relational algebra (1 to 4), Calculus(1 to 4) SQL 1 to 6).
5. Give per swimmer, the number of beaches visited