grails - 关于Grails的新手问题 “createCriteria”

Question

我是Grails条件构建器的新手，有人可以解释以下含义吗？

def c = Account.createCriteria()
         def results = c {

             like("holderFirstName", "Fred%")
             and {
                 between("balance", 500, 1000)
                 eq("branch", "London")
             }
             maxResults(10)
             order("holderLastName", "desc")
         }

是不是意思

Select * from account where
holderFirstName like 'fred%' and
(balance between 500 and 1000 **and**
branch='london')

Select * from account where
holderFirstName like 'fred%' and
(balance between 500 and 1000 **or**
branch='london')

如果我想一起使用“或”和“与”，该怎么做？

Answer 1

您的示例将执行为:

select * from account 
where holderFirstName like 'Fred%' 
and balance between 500 and 1000 
and branch = 'London'

暗示所有顶级条件都必须进行“与”运算。您可以创建与以下相同的条件:

def c = Account.createCriteria()
def results = c {
    like("holderFirstName", "Fred%")
    between("balance", 500, 1000)
    eq("branch", "London")
    maxResults(10)
    order("holderLastName", "desc")
}

要获取第二个查询，请使用以下条件:

def c = Account.createCriteria()
def results = c {
    like("holderFirstName", "Fred%")
    or {
        between("balance", 500, 1000)
        eq("branch", London")
    }
    maxResults(10)
    order("holderLastName", "desc")
}

嵌套 and / or闭包以获得更复杂的条件。