Dynamic namedQueries

Question

Is their a dynamic namedquery on grails? Im not sure if its the right term but, I mean a namedquery that can be true to all.

Something like:

namedQueries = {
 dynamicQuery{ term, name, value ->
   term(name, value)
 }
}

Then it can be called maybe like but not exactly:

def testClass = TestClass.dynamicQuery('eq', 'lastname', 'Bill').list()

and so you call it too like:

def testClass = TestClass.dynamicQuery('gt', 'id', 12).list()

This one might not work but is their something similar in grails?

UPDATE The idea is that so I can chained it as many as I want like:

 def testClass = TestClass.dynamicQuery('gt', 'id', 12).dynamicQuery('eq', 'stat', 11).list()

This is so that I dont have to create many namedqueries. I was hoping I can create one and use it multiple times.

Answer 1

Grails' createCriteria method generates Grails HibernateCriteriaBuilder instance, within which you can call invokeMethod method to dynamically create query criteria, which usually is defined by the standard DSL.

Here is a example in some controller:

private String dynamicCriteriaTest(String term, name,  value) {
    def c = TestClass.createCriteria()
    def param = []
    param << name
    param << value
    def result =  c.list{
        c.invokeMethod(term, param as Object[])
    }
    return result.toString()
} 

def test() {
    render dynamicCriteriaTest('eq','lastname','Bill')
}

That will get something you want.

---

update

If you want to call this method multiple times, pass the criteria parameters in an a List then execute the query:

    private List dynamicCriteriaTest(List param) {
        def c = TestClass.createCriteria()
        def paramList = param.collate(3)    //split the parameters into groups
        def result =  c.list{
            paramList.each { paramInstance ->
                def command = paramInstance[0]
                paramInstance.remove(0)
                c.invokeMethod(command, paramInstance as Object[])
            }
        }
        return result
    }

    def test() {
        ArrayList param = new ArrayList()
            //the 1st criteria
        param << 'gt'
        param << 'id'
        param << (long)12    //you have to check the Grails [HibernateCriteriaBuilder] API to make sure the parameter passed to `invokeMethod` is in the right type (e.g. **long** in this case)

            //the 2nd one
        param << 'eq'
        param << 'stat'
        param << (long)11

            //even more
        param << 'like'
        param << 'description'
        param << 'some text%'    

        render dynamicCriteriaTest(param)
    }

Answer 2

In Grails you have NamedQueries and also Where Queries. The example you give can possibly be implemented by using a namedqueries and placing this in a abstract domain class. Your domain classes should extend this abstract domain.