grails - Grails中的withCriteria和CreateCriteria有什么区别？

Question

它们之间有什么区别，为什么我们需要在哪里使用它们，我认为它们对我来说根本没有区别？

Answer 1

值得添加我在grails文档中遇到的createCriteria()。

Because that query includes pagination parameters (max and offset), this will return a PagedResultList which has a getTotalCount() method to return the total number of matching records for pagination. Two queries are still run, but they are run for you and the results and total count are combined in the PagedResultList.

Source

这意味着您可以使用 getTotalCount()而不需要发起 call (这是为您而做的)。这非常有帮助。示例文档显示:

def c = Account.createCriteria()
def results = c.list (max: 10, offset: 10) {
    like("holderFirstName", "Fred%")
    and {
        between("balance", 500, 1000)
        eq("branch", "London")
    }
    order("holderLastName", "desc")
}
println "Rendering ${results.size()} Accounts of ${results.totalCount}"

使用 withCriteria()时此功能不可用。