Levure Creating a database

Creating a database in a Levure application

SQL Yoga allows you to create a database from scratch using a YAML file as well.

1. Create a migrate folder in your ./app/database folder.
2. Create a file named 001_create_tables.yml in the ./app/database/migrate folder.
3. Add the following YAML to the file:

migration:
  create tables:

4. For each table you want to create add the following:

    - name: TABLE_NAME
      fields:
        - { name: FIELD_NAME, type: FIELD_TYPE }

5. Open your Levure application open in the Livecode IDE.
6. In the message box call sqlyogadev_runMigrations;put the result.

Your database will now have the tables and fields you specified and the ./app/database/schema.yml file will contain the new schema. If any errors occurred they will be reported in the message box due to the addition of ;put the result.

SQL Yoga will create a table named schema with a version column. The version of the last run migration will be stored in this table. This is how SQL Yoga knows the last migration to run. In this case the value in the version column will be 1.

You can also create new records in the migration file.

migration:
  create tables:
    ...
  create records:
    - table: TABLE_NAME
      records:
        - { FIELD_NAME: FIELD_VALUE, FIELD_NAME: FIELD_VALUE }

Modifying your database schema

1. If you need to modify your database later on create a file named 002_create_tables.yml in the ./app/database/migrate folder.
2. Populate the YAML file as described above.
3. In the message box call sqlyogadev_runMigrations;put the result. Since SQL Yoga stored the migration version number previously it will only process the 002_create_tables.yml file.