John works as a Database Administrator in www.company.com Inc. The company has a SQL Server
database. John wants to create a table named employees in the database. The table will have the id,
firstname, lastname, and dateofbirth columns. John has to ensure that the lastname column does
not allow null values. Which of the following queries will he use to accomplish the task?
A.
CREATE TABLE employees (id INTEGER PRIMARY KEY, firstname CHAR(50)NULL, lastname CHAR
(75)NOT NULL, dateofbirth DATE NULL);
B.
CREATE TABLE employees (id INTEGER PRIMARY KEY, firstname CHAR(50)NULL, lastname CHAR
(75), dateofbirth NULL);
C.
CREATE TABLE employees (id INTEGER PRIMARY KEY, firstname CHAR(50)NULL, lastname CHAR
(75) NOT NULL);
D.
CREATE TABLE employees (id INTEGER PRIMARY KEY, firstname CHAR(50)NULL, lastname CHAR
(75), dateofbirth DATE NULL);
Explanation:
In this query, all the columns are created according to the requirement and the lastname column is
not allowing the null values to be entered.
Answer D is incorrect. In this query, the lastname column is allowing the null values to be entered.
Answer C is incorrect. In this query, the dateofbirth column is missing.
Answer B is incorrect. In this query, the data type of the dateofbirth column is missing.