MigrationBackup

File: src/Services/MigrationBackup.php
Facade: Unusualify\Modularous\Facades\MigrationBackup

Provides data-safe migration helpers that snapshot table data and schema to the Laravel cache before running destructive migrations, then restore rows if a rollback is needed.

Supports MySQL, PostgreSQL, and SQLite. All cache keys are namespaced by the calling migration's filename, so concurrent migrations never collide.

How It Works

1. Before migration — call backup(). The service snapshots the table's current rows and schema (column types, nullability, defaults, foreign keys) to the Laravel cache.
2. Run migration — execute your Schema:: changes normally.
3. On rollback — call restore(). The service re-inserts backed-up rows, adapting them to the current schema (new columns get type-appropriate defaults; removed columns are silently dropped).
4. After rollback — call clearBackup() to remove the cache entries.

Key Methods

Method	Signature	Description
backup	backup(string $table, ?array $columns, bool $includeRelated): void	Snapshot a table to cache. When $includeRelated is true (default), FK-referenced tables are also snapshotted.
restore	restore(?string $table): bool	Restore rows from the snapshot. Pass null to restore every table backed up by this migration. Returns true on success.
clearBackup	clearBackup(?string $table): void	Remove cached snapshots. Pass null to clear all snapshots for this migration.
getBackup	getBackup(?string $table): ?array	Inspect the raw snapshot data stored in cache.
getSchemaHistory	getSchemaHistory(?string $table): array	Return a log of column additions/removals/modifications detected during restore.

Usage in Migrations

use Unusualify\Modularous\Services\MigrationBackup;

class AddSkuToProductsTable extends Migration
{
    public function up(): void
    {
        $backup = app(MigrationBackup::class);
        $backup->backup('products');

        Schema::table('products', function (Blueprint $table) {
            $table->dropColumn('legacy_code');
            $table->string('sku')->unique();
        });
    }

    public function down(): void
    {
        $backup = app(MigrationBackup::class);
        $backup->restore('products');
        $backup->clearBackup('products');
    }
}

Foreign Key Handling

During restore, foreign key constraints are temporarily disabled:

Driver	Statement
MySQL	SET FOREIGN_KEY_CHECKS=0
PostgreSQL	SET CONSTRAINTS ALL DEFERRED
SQLite	PRAGMA foreign_keys=OFF

Constraints are re-enabled in a finally block, even if restore fails.

Schema Adaptation

When restoring rows after a schema change, the service:

• Removes columns that no longer exist from the row data before inserting
• Fills new columns with a type-appropriate default:

Column type	Default
varchar, text, char	''
int, bigint, smallint	0
decimal, float, double	0.0
boolean, tinyint(1)	false
datetime, timestamp, date, json	null

Cache Key Format

migration_backup_{migration-file-slug}_{table-slug}

All backup keys for a migration are tracked under migration_backups_{migration-file-slug}, which is also cleared by clearBackup().