# 🚀 Migration Quick Reference

## Daily Development Workflow

### Starting Development (Auto-runs Migrations)
```bash
npm run dev
```
✅ **This will automatically run all new migrations before starting the server!**

### Run Migrations Only
```bash
npm run migrate
```

## Adding a New Migration (3 Steps)

### 1️⃣ Create Migration File
Location: `src/migrations/YYYYMMDD-description.ts`

```typescript
import { QueryInterface, DataTypes } from 'sequelize';

export async function up(queryInterface: QueryInterface): Promise<void> {
  await queryInterface.addColumn('table_name', 'column_name', {
    type: DataTypes.STRING,
    allowNull: true,
  });
  console.log('✅ Migration completed');
}

export async function down(queryInterface: QueryInterface): Promise<void> {
  await queryInterface.removeColumn('table_name', 'column_name');
  console.log('✅ Rollback completed');
}
```

### 2️⃣ Register in `src/scripts/migrate.ts`
```typescript
// Add import at top
import * as m15 from '../migrations/YYYYMMDD-description';

// Add execution in run() function
await (m15 as any).up(sequelize.getQueryInterface());
```

### 3️⃣ Test
```bash
npm run migrate
```

## Common Operations

### Add Column
```typescript
await queryInterface.addColumn('table', 'column', {
  type: DataTypes.STRING(100),
  allowNull: false,
  defaultValue: 'value'
});
```

### Add Foreign Key
```typescript
await queryInterface.addColumn('table', 'foreign_id', {
  type: DataTypes.UUID,
  references: { model: 'other_table', key: 'id' },
  onUpdate: 'CASCADE',
  onDelete: 'SET NULL'
});
```

### Add Index
```typescript
await queryInterface.addIndex('table', ['column'], {
  name: 'idx_table_column'
});
```

### Create Table
```typescript
await queryInterface.createTable('new_table', {
  id: {
    type: DataTypes.UUID,
    defaultValue: DataTypes.UUIDV4,
    primaryKey: true
  },
  name: DataTypes.STRING(100),
  created_at: DataTypes.DATE,
  updated_at: DataTypes.DATE
});
```

## What's New ✨

### Latest Migration: Skip Approver Functionality
- **File**: `20251105-add-skip-fields-to-approval-levels.ts`
- **Added Fields**:
  - `is_skipped` - Boolean flag
  - `skipped_at` - Timestamp
  - `skipped_by` - User reference
  - `skip_reason` - Text explanation
- **Index**: Partial index on `is_skipped = TRUE`

## Troubleshooting

| Issue | Solution |
|-------|----------|
| Migration fails | Check console error, fix migration file, re-run |
| Column exists error | Migration partially ran - add idempotent checks |
| Server won't start | Fix migration first, it blocks startup |

## 📚 Full Documentation
See `MIGRATION_WORKFLOW.md` for comprehensive guide.

---
**Auto-Migration**: ✅ Enabled  
**Total Migrations**: 14  
**Latest**: 2025-11-05