How to export relational model changes as a SQL script
When you work Model First and you have synced the relational model data with the Abstract Entity Model, the changes aren't applied to your real RDBMS schema, you have to do that by running a script which is generated from the changes made. To do so, you have to export the relational model data as a Database Schema Update Script.
You can also decide to use a create script instead. This is also explained in detail in the Export Relational Model Data as Database Schema Create / Update Scripts section.