Alter the CUSTOMERS table to change the primary key to Email to ensure each customer is uniquely identified by their email address.
Question
Alter the CUSTOMERS table to change the primary key to Email to ensure each customer is uniquely identified by their email address.
Solution
To alter the CUSTOMERS table and change the primary key to Email, you would follow these steps:
- First, you need to drop the existing primary key. You can do this with the following SQL command:
ALTER TABLE CUSTOMERS
DROP PRIMARY KEY;
- After dropping the existing primary key, you can now set the Email column as the new primary key. Use the following SQL command:
ALTER TABLE CUSTOMERS
ADD PRIMARY KEY (Email);
Please note that all email addresses in the Email column must be unique and not null before you can set it as a primary key. If there are any duplicate or null values, you will need to resolve these issues before running the above command.
Similar Questions
Alter the USERS table to change the primary key to Email to ensure uniqueness based on email addresses.
Alter the CUSTOMERS table to change the primary key to Email to ensure each customer is uniquely identified by their email address.Drop the primary key from the BOOKINGS table as it is no longer required.
Alter the CUSTOMERS table to change the primary key from CustomerID to Email for better identification of customers.Alter the RESERVATIONS table to allow ReservationTime to be nullable in case some reservations do not have a specific time set.
Charles is developing a travel booking system to manage customers, bookings, and payments. The system needs to handle three main types of data: CUSTOMERS, BOOKINGS, and PAYMENTS. To perform this the user needs to create the following tables with the mentioned constraints: symbol refers to the primary key NN refers to Not NULL After creating the tables, Charles needs to:Alter the CUSTOMERS table to change the primary key to Email to ensure each customer is uniquely identified by their email address.Drop the primary key from the BOOKINGS table as it is no longer required.Note: The user must write only the query to create, alter, and drop the table. The query to display the description of the table is already given.Input format :No console inputOutput format :The output displays the successful table creation status and the structure of all three tablesRefer to the sample output.Sample test cases :Input 1 :Output 1 :Table CUSTOMERS created.Table BOOKINGS created.Table PAYMENTS created.Table CUSTOMERS altered.Table CUSTOMERS altered.Table BOOKINGS altered. Name Null? Type _____________ ___________ ________________ CUSTOMERID NOT NULL NUMBER FIRSTNAME VARCHAR2(100) LASTNAME VARCHAR2(100) EMAIL NOT NULL VARCHAR2(100) Name Null? Type ______________ ___________ ________________ BOOKINGID NOT NULL NUMBER CUSTOMERID NUMBER BOOKINGDATE DATE DESTINATION VARCHAR2(100) Name Null? Type ______________ ___________ _________ PAYMENTID NOT NULL NUMBER BOOKINGID NUMBER AMOUNT NUMBER PAYMENTDATE DATE TABLE_NAME COLUMN_NAME POSITION STATUS _____________ ______________ ___________ __________ CUSTOMERS EMAIL 1 ENABLED 1 row selected.
A database administrator is setting up a new table that will contain customer information. The fields include name, address, company, phone, email, and customer ID. The administrator is using the customer ID to uniquely identify each customer record. Which of the following BEST describes the customer ID field?answerForeign keyPublic keyPrimary keyPrivate key
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.