Issue type:

• question
• bug report
• feature request
• documentation issue

Database system/driver:

• cordova
• mongodb
• mssql
• mysql / mariadb
• oracle
• postgres
• sqlite
• sqljs
• websql

TypeORM version:

• latest
• @next
• 0.x.x (or put your version here)

Steps to reproduce or a small repository showing the problem:

1. Create entity, e.g: User with column email
2. Generate and run migration typeorm migrations:generate -n Init && typeorm migrations:run
3. Add new column createdAt with default set to () => 'NOW()'
4. Generate and run migration typeorm migrations:generate -n AlterCreated && typeorm migrations:run
5. Add new column name
6. If we generate migration again typeorm migrations:generate -n Test, the queries that generated because the changes on step 3 will show up again