Altering-Database.md

Altering the Database

Adding Scripts

Note

Scripts that have previously been executed will not be re-executed.

1. Create a new .sql script under the scripts folder.
2. Mark your script as an Embedded Resource.
3. Rebuild the project and run the command

Important

The scripts are running in alphabetical order so make sure that you follow the ScriptXXXX_<script name>. If you want to run a new script before an old script, you will need to rename the scripts accordingly.

Updating

When you want to alter your database schema, you have two options:

1. Create a script that will make the required changes

Important

This is the method that we recommend you perform your changes.

Create a new .sql script using the instructions above.

2. Alter the script that you want to make a change to

Caution

This method is not recommended and you should use it only if there is no other option available. It might lead to errors and potential data loss.

DbUp uses a special table called SchemaVersions to keep track of the scripts that have been executed. This way, it avoids running the same scripts again if they have not been modified since the last run. The journal table stores the history of all script runs in the database.

If you want to alter a preexisting script, you need to modify the SchemaVersions table and remove the run for the modified script, as well as all dependent scripts.

This is an error prone procedure, and we recommend against using it.