⏰ MySQL Data Types

MySQL provides a variety of data types to store different kinds of data. These are categorized into three main groups:

1. Numeric Data Types:
- INT, BIGINT, SMALLINT, TINYINT: For whole numbers.
- DECIMAL, FLOAT, DOUBLE: For real numbers with decimal points.
- BIT: For binary values.
- Example:

            CREATE TABLE numeric_example (
                id INT,
                amount DECIMAL(10, 2)
            );
            
            

1. String Data Types:
- CHAR, VARCHAR: For fixed and variable-length strings.
- TEXT: For large text.
- BLOB: For binary large objects like images.
- Example:

            CREATE TABLE string_example (
                name VARCHAR(100),
                description TEXT
            );
            
            

1. Date and Time Data Types:
- DATE, DATETIME, TIMESTAMP: For date and time values.
- YEAR: For storing a year.
- Example:

                CREATE TABLE datetime_example (
                    created_at DATETIME,
                    year_of_joining YEAR
                );
                
                

Interview Questions:

- Q1: What is the difference between CHAR and VARCHAR?
A1: CHAR has a fixed length, while VARCHAR has a variable length. VARCHAR is more storage-efficient for varying-length data.
- Q2: When should you use DECIMAL instead of FLOAT?
A2: Use DECIMAL for precise calculations (e.g., financial data) and FLOAT for approximate values where precision is less critical.