📊 Capítulo 05: Migrations & Schema Builder

Especialização Backend com PHP & Laravel

🗺️ O Fluxo de Versionamento de Banco com Migrations

flowchart TD
    ARTISAN["php artisan make:migration create_pedidos_table"]
    --> SCHEMA["Schema::create('pedidos', function (Blueprint $table) { ... })"]
    --> UP["$table->id(); $table->foreignId('usuario_id')->constrained();"]
    --> MIGRATE["php artisan migrate"]
    --> DB_VERSION["Tabela migrations registra batch de execução no PostgreSQL / MySQL"]
    --> ROLLBACK["php artisan migrate:rollback (Executa método down())"]

    style ARTISAN fill:#ede7f6,stroke:#512da8,stroke-width:2px
    style SCHEMA fill:#fff3e0,stroke:#ff9800,stroke-width:2px
    style UP fill:#e8f5e9,stroke:#4caf50,stroke-width:1.5px
    style MIGRATE fill:#e1f5fe,stroke:#03a9f4,stroke-width:2px
    style DB_VERSION fill:#c8e6c9,stroke:#2e7d32,stroke-width:1.5px
    style ROLLBACK fill:#ffebee,stroke:#d32f2f,stroke-width:1.5px

🎯 Slide 1: Sintaxe Moderna do Schema Builder

Schema::create('produtos', function (Blueprint $table) {
    $table->id();
    $table->string('nome', 120)->index();
    $table->decimal('preco', 10, 2);
    $table->foreignId('categoria_id')->constrained('categorias')->cascadeOnDelete();
    $table->json('atributos')->nullable();
    $table->timestamps();
    $table->softDeletes();
});

🎯 Slide 2: Anonymous Migrations no Laravel

• As migrações modernas do Laravel retornam uma classe anônima (return new class extends Migration), eliminando conflitos de nomenclatura de classes em projetos grandes!

🎯 Slide 3: Boas Práticas de Índices e Chaves Estrangeiras

• foreignId()->constrained(): Cria a coluna unsigned bigint e a constraint de chave estrangeira em 1 única linha.

• Índices Compostos: $table->index(['status', 'created_at']) para acelerar queries com múltiplos filtros.