migrations

Name: Migrations Description: Database schema change files. Always create new files for changes — never modify existing migrations. Use descriptive names, proper foreign key constraints, and reversible down() methods. Compatible Agents: general-purpose, backend Tags: database/migrations/**/*.php, laravel, php, backend, database, migration, schema

Rules

• Always create new migration files for database changes — never modify existing migration files
• Use descriptive names: create_invoices_table, add_status_to_invoices_table
• Implement both up() and down() methods — down() must fully reverse up()
• Group related columns logically: IDs first, then data, then timestamps
• Use enum string values for status columns: $table->string('status')->default('draft')
• Add indexes on columns used in WHERE clauses and foreign keys
• Use foreignId()->constrained()->cascadeOnDelete() for foreign keys
• Keep migrations focused — one concern per migration

Examples

public function up(): void
{
    Schema::create('invoices', function (Blueprint $table) {
        $table->id();
        $table->foreignId('order_id')->constrained()->cascadeOnDelete();
        $table->foreignId('user_id')->constrained()->cascadeOnDelete();
        $table->string('status')->default('draft');
        $table->decimal('amount', 10, 2);
        $table->date('due_date');
        $table->timestamp('paid_at')->nullable();
        $table->timestamps();

        $table->index('status');
    });
}

public function down(): void
{
    Schema::dropIfExists('invoices');
}

// Adding a column to an existing table
public function up(): void
{
    Schema::table('invoices', function (Blueprint $table) {
        $table->string('reference')->nullable()->after('status');
    });
}

public function down(): void
{
    Schema::table('invoices', function (Blueprint $table) {
        $table->dropColumn('reference');
    });
}

Anti-Patterns

• Modifying existing migration files instead of creating new ones
• Using an integer default for status columns instead of a string enum value
• Omitting the down() method or leaving it empty
• Not adding indexes on foreign key columns and frequently queried columns
• Creating a single migration that makes multiple unrelated schema changes
• Using $table->integer('status') instead of $table->string('status')->default('...')

References

• Laravel Migrations
• Related: Models/SKILL.md — models reflect the schema defined in migrations
• Related: Enums/SKILL.md — enum string values used as migration defaults