Question

Boold Guest_ID Name • Tel No Guest CHAR (7) VARCHAR2 (50) CHAR (15) TAP - Booking Number • Room Number • From_Date To Date • Rate_per_night F Guest_ID CHAR (15) SHARE DATE DATE NUMBER (62) CHAR (0) Inspect the above ER diagram and answer the following questions: 1. Write a SQL statement to create the "Guest' table. (4 marks) 2. Write a SQL statement to set the column "Guest_ID" as the primary key of the "Guest' table. (4 marks)

Answer 1

Creating a table : Without a Primary Key

*************************************

create table Guest
(

Guest_ID CHAR(7),
Name VARCHAR2(50),
Tel_No CHAR(15)

)

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setting the column Guest_ID as a primary key:

ALTER TABLE Guest ADD PRIMARY KEY (Guest_ID);

Now Guest_ID is a primary key and it won't accept duplicate values as well as null values. Because Primary Key is by default unique and not null.