About Schema Visualization

Database schema visualization helps you understand the structure of your database tables, including columns, data types, and constraints. This is essential for database design, documentation, and debugging.

What Gets Parsed

• Table Names: The name of each table defined
• Columns: Column names and their data types
• Column Constraints: NOT NULL, UNIQUE, DEFAULT, AUTO_INCREMENT, etc.
• Table Constraints: PRIMARY KEY, FOREIGN KEY, CHECK, INDEX
• Relationships: Foreign key references between tables

Common Data Types

Category	Data Types	Usage
Numeric	INT, BIGINT, DECIMAL, FLOAT	Numbers, IDs, prices
String	VARCHAR, CHAR, TEXT	Names, descriptions, content
Date/Time	DATE, DATETIME, TIMESTAMP	Dates, timestamps
Boolean	BOOLEAN, TINYINT(1)	True/false values
Binary	BLOB, VARBINARY	Images, files

Common Constraints

• PRIMARY KEY: Uniquely identifies each row
• FOREIGN KEY: Creates relationship with another table
• UNIQUE: Ensures all values in column are different
• NOT NULL: Column cannot contain NULL values
• DEFAULT: Sets default value for column
• CHECK: Validates data meets specific condition
• AUTO_INCREMENT: Automatically generates unique numbers

Example Schema

CREATE TABLE users (
    id INT PRIMARY KEY AUTO_INCREMENT,
    username VARCHAR(50) NOT NULL UNIQUE,
    email VARCHAR(100) NOT NULL UNIQUE,
    password_hash VARCHAR(255) NOT NULL,
    is_active BOOLEAN DEFAULT TRUE,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);

CREATE TABLE posts (
    id INT PRIMARY KEY AUTO_INCREMENT,
    user_id INT NOT NULL,
    title VARCHAR(200) NOT NULL,
    content TEXT,
    status ENUM('draft', 'published', 'archived') DEFAULT 'draft',
    published_at TIMESTAMP NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
    INDEX idx_status (status),
    INDEX idx_user_id (user_id)
);

Best Practices

• Always define primary keys for tables
• Use appropriate data types to save storage
• Add NOT NULL constraints where applicable
• Create indexes on frequently queried columns
• Use foreign keys to maintain referential integrity
• Add timestamps for record tracking
• Document complex constraints and relationships