How do you bulk delete records in Grails/GORM?

Question

I have a table which has records that need to be periodically cleared according to a set of criteria.

I was expecting that I could use the criteria builder to just delete the records, but that fails because there is no delete method on criteria...

def c = Agency.createCriteria() c.delete {     eq("agency", "XXX")   } 

So I thought maybe I first query for the set and then delete that...

def c = Agency.createCriteria() def deletions = c {     eq("agency", "XXX")   } deletions.delete 

This also fails for the same reason, different object.

So what is the right way to do this? It seems excessive (perverse) that I would have to iterate through the entire result set calling delete() on each item.

I know I can form a query to execute directly either in HQL or SQL but that feels wrong too. Is the criteria builder only meant for retrieval?

Thanks

Answer 1

With Grails 2.0 you can use a detached query like this:

Agency.where { }.deleteAll() 

Note that you don't get the listeners and whatnot executed, but it does execute through to the database, AND it is compatible with the mocked domain stuff, as in:

void testWhatever() {     mockDomain(Agency, [])     saveABunchOfAgencies() // saves 10 of 'em     assert Agency.count() == 10      Agency.where { }.deleteAll()      assert Agency.count() == 0   // Joy! } 

That being said the GORM unit test mocks have a bunch of gotchas but are in general pretty neat.

Answer 2

From the User Guide about deleting objects:

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"])