Question

If I were retrieving the data I wanted from a plain sql query, the following would suffice:

select * from stvterm where stvterm_code > TT_STUDENT.STU_GENERAL.F_Get_Current_term()

I have a grails domain set up correctly for this table, and I can run the following code successfully:

def a = SaturnStvterm.findAll("from SaturnStvterm as s where id > 201797") as JSON
a.render(response)
return false

In other words, I can hardcode in the results from the Oracle function and have the HQL run correctly, but it chokes any way that I can figure to try it with the function. I have read through some of the documentation on Hibernate about using procs and functions, but I’m having trouble making much sense of it. Can anyone give me a hint as to the proper way to handle this?

Also, since I think it is probably relevant, there aren’t any synonyms in place that would allow the function to be called without qualifying it as schema.package.function(). I’m sure that’ll make things more difficult. This is all for Grails 1.3.7, though I could use a later version if needed.

Answer 1

To call a function in HQL, the SQL dialect must be aware of it. You can add your function at runtime in BootStrap.groovy like this:

import org.hibernate.dialect.function.SQLFunctionTemplate
import org.hibernate.Hibernate

def dialect = applicationContext.sessionFactory.dialect
def getCurrentTerm = new SQLFunctionTemplate(Hibernate.INTEGER, "TT_STUDENT.STU_GENERAL.F_Get_Current_term()")
dialect.registerFunction('F_Get_Current_term', getCurrentTerm)

Once registered, you should be able to call the function in your queries:

def a = SaturnStvterm.findAll("from SaturnStvterm as s where id > TT_STUDENT.STU_GENERAL.F_Get_Current_term()")