java - How to jUnit Assert a Grails Controller Update of a Database column?

I have a grails controller which takes a simple string and updates a column in the DB by id. I want to write a jUnit test for this operation to make sure the update went through correctly....

  @Test
 void "testUpdateNameOnMonsterById"() {

    controller.params.id = 8;
    controller.params.name = 'Godzilla';


    controller.updateMosterNameById();
    // what are the different jUnit assertetions that need to happen at this point?

For example should I query the DB and do assertEquals or assertTrue?

Any sample code with jUnit asserts would be greatly appreciated.