(Quick Reference)

7.3.2 Deleting Objects - Reference Documentation

Authors: Graeme Rocher, Peter Ledbrook, Marc Palmer, Jeff Brown, Luke Daley, Burt Beckwith, Lari Hotari

Version: 3.1.4

7.3.2 Deleting Objects

An example of the delete method can be seen below:

def p = Person.get(1)
p.delete()

As with saves, Hibernate will use transactional write-behind to perform the delete; to perform the delete in-place you can use the flush argument:

def p = Person.get(1)
p.delete(flush: true)

Using the flush argument lets you catch any errors that occur during a delete. A common error that may occur is if you violate a database constraint, although this is normally down to a programming or schema error. The following example shows how to catch a DataIntegrityViolationException that is thrown when you violate the database constraints:

def p = Person.get(1)

try { p.delete(flush: true) } catch (org.springframework.dao.DataIntegrityViolationException e) { flash.message = "Could not delete person ${p.name}" redirect(action: "show", id: p.id) }

Note that Grails does not supply a deleteAll method as deleting data is discouraged and can often be avoided through boolean flags/logic.

If you really need to batch delete data you can use the executeUpdate method to do batch DML statements:

Customer.executeUpdate("delete Customer c where c.name = :oldName",
                       [oldName: "Fred"])