Databases, Tables, Columns, Data Types, and Schema Basics
Build a strong foundation in how MySQL organizes structured information through schemas and tables.
Inside this chapter
- What a Database and Table Mean
- A Simple Table Example
- Common Data Types
- Why Data Type Choice Matters
- Business Example
Series navigation
Study the chapters in order for the clearest path from MySQL basics to advanced performance, consistency, and production operations. Use the navigation at the bottom to move smoothly through the full tutorial series.
What a Database and Table Mean
A database is a named container for related tables and other objects. A table stores rows of records, while columns define the shape of each record. This structure is the core of relational data design.
A Simple Table Example
CREATE TABLE students (
id INT PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(100) NOT NULL,
email VARCHAR(255) UNIQUE,
enrolled_on DATE
);This example shows column types, primary key usage, nullability, and uniqueness rules.
Common Data Types
INTfor integer valuesVARCHARfor variable-length stringsTEXTfor larger textual contentDATEandDATETIMEfor time-related valuesDECIMALfor precise financial amountsBOOLEANor tiny integer style fields for yes/no state
Why Data Type Choice Matters
Good type selection affects storage, performance, clarity, constraints, and application correctness. Financial numbers, for example, should usually avoid floating types where exact precision matters.
Business Example
An employee table might store employee ID, full name, department, joining date, salary, and status flags. Schema design makes those business concepts explicit and queryable.