SQL Data Types Interview Questions

    Question 1: VARCHAR vs CHAR Data Types

    What is the difference between VARCHAR and CHAR data types?

    Question 2: INT vs BIGINT Comparison

    What is the difference between INT and BIGINT data types?

    Question 3: Numeric Data Type Operations

    In a products table with columns (product_id INT, price DECIMAL(10,2), discount_percent INT), write a query to calculate the final price after applying discount for products with price greater than $100.

    Question 4: TEXT vs VARCHAR Length Limits

    What is the difference between TEXT and VARCHAR data types?

    Question 5: NULL Data Type Handling

    How do different data types handle NULL values?

    Question 6: ENUM Data Type Usage

    What is ENUM data type and when should it be used?

    Question 7: Date Function Operations

    Given an orders table with columns (order_id INT, order_date DATE, delivery_date DATE), write a query to find orders where delivery took more than 7 days.

    Question 8: String Function with Data Types

    Given a users table with columns (user_id INT, username VARCHAR(50), email VARCHAR(100)), write a query to find all users whose username length is greater than 8 characters.

    Question 9: AUTO_INCREMENT and IDENTITY

    What is AUTO_INCREMENT/IDENTITY and which data types support it?

    Question 10: Mixed Data Type Conversion

    In an employees table with columns (emp_id INT, salary DECIMAL(10,2), hire_date DATE, is_active BOOLEAN), write a query to show employee ID and years of service for active employees hired before 2020.