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Module 13 – Solutions 13.7
5.31 Show that SQL is relationally complete.
Hint: Allow the students to show that each of the relational algebra operations can be
expressed in SQL.
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13.3 Chapter 6 SQL: Data Definition
Solutions and hints of some exercises
6.7 CREATE TABLE Hotel(
hotelNo CHAR(4) NOT NULL,
hotelName VARCHAR(20) NOT NULL,
city VARCHAR(50) NOT NULL,
PRIMARY KEY (hotelNo));
Or
CREATE DOMAIN HotelNumber AS CHAR(4);
CREATE TABLE Hotel(
hotelNo HotelNumber NOT NULL,
hotelName VARCHAR(20) NOT NULL,
city VARCHAR(50) NOT NULL,
PRIMARY KEY (hotelNo));
6.8 Now create the Room, Booking, and Guest tables using the integrity enhancement
features of SQL with the following constraints:
(a) Type must be one of Single, Double, or Family.
(b) Price must be between £10 and £100.
(c) roomNo must be between 1 and 100.
(d) dateFrom and dateTo must be greater than today’s date.
(e) The same room cannot be double booked.
(f)
The same guest cannot have overlapping bookings.