grails - 寻找嵌套对象的存在

Question

class Car {
    String carname
}

class Factory {
    Car car
    String factoryname
}

如何检查是否存在带有 Factory和 factoryname == "Kia"的对象 carname == "newmodel"？

Answer 1

您可以使用 createCriteria()方法和别名。

def cName = 'newmodel'
def fName = 'Kia'
def objects = Factory.createCriteria().count() {
    createAlias('car', 'c'),
    eq('c.carname', cName)
    eq('factoryname', fName)
}
boolean isThere = objects