from orator.migrations import Migration


class CreateCrossReferencesTable(Migration):

    def up(self):
        """
        Run the migrations.
        """
        with self.schema.create('crossreferences') as table:
            table.integer('passage_id1')
            table.integer('passage_id2')
            table.timestamps()
            table.small_integer('relevance').default(0)
            table.foreign('passage_id1').references('id').on('passages')
            table.foreign('passage_id2').references('id').on('passages')
            table.primary(['passage_id1', 'passage_id2'])

    def down(self):
        """
        Revert the migrations.
        """
        self.schema.drop('crossreferences')