SQL Quiz

Create a SQL query to create a table named 'Students' with columns 'id' of type INT, 'name' of type VARCHAR(50), and 'age' of type INT.

• CREATE TABLE Students (id VARCHAR(50), name INT, age VARCHAR(50));

• INSERT INTO Students (id INT, name VARCHAR(50), age INT);

• CREATE TABLE Students (id INT, name VARCHAR(50), age INT);

• UPDATE Students SET id INT, name VARCHAR(50), age INT;

Write a SQL query to create a table named 'Employees' with columns 'emp_id' of type INT, 'emp_name' of type VARCHAR(50), 'emp_salary' of type DECIMAL(10,2), and 'emp_join_date' of type DATE.

• CREATE TABLE Employees (emp_id INT, emp_name VARCHAR(50), emp_salary DECIMAL(10,2), emp_join_date DATE);

• CREATE TABLE Employees (emp_id DECIMAL(10,2), emp_name DATE, emp_salary VARCHAR(50), emp_join_date INT);

• CREATE TABLE Employees (emp_id DATE, emp_name DECIMAL(10,2), emp_salary INT, emp_join_date VARCHAR(50));

• CREATE TABLE Employees (emp_id VARCHAR(50), emp_name INT, emp_salary DATE, emp_join_date DECIMAL(10,2));

Design a SQL query to create a table named 'Products' with columns 'product_id' of type INT, 'product_name' of type VARCHAR(100), 'price' of type DECIMAL(8,2), and 'quantity' of type INT.

• CREATE TABLE Products (product_id VARCHAR(50), product_name VARCHAR(255), price DECIMAL(10,2), quantity INT);

• CREATE TABLE Products (product_id INT, product_name VARCHAR(100), price DECIMAL(8,2), quantity INT);

• CREATE TABLE Products (id INT, name VARCHAR(100), price DECIMAL(8,2), qty INT);

• CREATE TABLE Products (product_id INT, product_name TEXT, price DECIMAL(8,2), quantity INT);

Explain the data types in SQL with examples.

• Data types in SQL include apple, banana, orange, grape, and watermelon among others.

• Data types in SQL include integer, float, char, varchar, date, and boolean among others.

• Data types in SQL include cat, dog, bird, fish, and rabbit among others.

• Data types in SQL include red, blue, green, yellow, and purple among others.

What are the different data types available in SQL? Provide examples for each data type.

• Text, Number, DateTime

• String, Boolean, Float

• Character, Integer, Boolean

• INT, VARCHAR, DATE

Discuss the importance of data types in SQL and how they are used in table creation.

• Data types in SQL are used in table creation to specify the color of the text

• Data types in SQL are important for defining the type of data that can be stored in a column. They are used in table creation to specify the type of data that each column can hold, such as integer, text, date, etc.

• Data types in SQL are used in table creation to specify the type of font used

• Data types in SQL are not important for defining the type of data that can be stored in a column

Explain the concept of constraints in SQL and provide examples of different types of constraints.

• Constraints in SQL are used to enhance the performance of queries

• Constraints in SQL are rules that are used to limit the type of data that can go into a table. Examples of constraints include NOT NULL, UNIQUE, PRIMARY KEY, FOREIGN KEY, and CHECK constraints.

• Examples of constraints include formatting rules for data input

• Constraints in SQL are only applicable to numeric data types

What is a primary key in SQL and how is it different from other constraints?

• It is used for sorting the records in a table

• It allows for duplicate values in the table

• It is not a constraint in SQL

• It uniquely identifies each record and does not allow for duplicate or null values.

Explain the significance of primary key in SQL and provide an example of its usage in table creation.

• The primary key in SQL is used for sorting the records in a table. Example: CREATE TABLE employees (id INT PRIMARY KEY, name VARCHAR(50));

• Primary key in SQL is used to store duplicate values in a table. Example: CREATE TABLE products (id INT PRIMARY KEY, name VARCHAR(50));

• The primary key in SQL is used to link two tables together. Example: CREATE TABLE orders (id INT PRIMARY KEY, product_id INT);

• The significance of primary key in SQL is to uniquely identify each record in a table and maintain data integrity. Example: CREATE TABLE students (id INT PRIMARY KEY, name VARCHAR(50));

What is a foreign key in SQL and how is it used to establish relationships between tables?

• It is a function used to calculate the average of the primary key values

• It is a field that stores the data type of the primary key

• It is a field in a table that establishes a link to the primary key of another table to create a relationship between the tables.

• It is a table that contains all the primary keys from other tables