How to use migrations in TypeORM?

TypeORM's Migration is an important tool for managing database schema changes:

1. Create migration:

   bash
   typeorm migration:generate -n MigrationName

2. Run migration:

   bash
   typeorm migration:run

3. Rollback migration:

   bash
   typeorm migration:revert

4. Migration file structure:

   • up(): Execute migration, create or modify table structure
   • down(): Rollback migration, undo the operations of up()

5. Using in code:

   typescript
   await dataSource.runMigrations();
   await dataSource.undoLastMigration();

Advantages of migrations include:

• Version control database structure
• Keep database synchronized during team collaboration
• Can rollback to previous versions
• Support safe deployment in production environments

It's recommended to generate migration files after each entity modification during development, and test migration and rollback operations before deployment.