与Criteria两级深层关联渴望获取Grails [英] withCriteria two level deep association eager fetch grails

问题描述

我希望加载一个结构，在关联链中深入两层。

I'd like to eager load a structure, two levels deep in an association chain. Something along the lines of:

class TopLevel {
    String name

    LevelOne levelOne
}    

class LevelOne {
    String name

    LevelTwo levelTwo
}

class LevelTwo {
    String name
}

我想加载整个结构。搜索我发现这个例子，但它没有奏效。

I'd like to load the entire structure. Searching around I found this example, but it didn't work. The "println" generated a query to the LevelTwo table.

def result = TopLevel.withCriteria {
    eq('name', 'test')
    fetchMode "levelOne", FetchMode.JOIN
    levelOne {
        fetchMode "levelTwo", FetchMode.JOIN
    }
}

println result.levelOne.levelTwo.name

感谢任何帮助！

- Steve

Appreciate any help!
- Steve

推荐答案

让它工作。以下是秘诀：

Got it working. Here's the secret sauce:

def result = TopLevel.withCriteria {
    eq('name', 'test')
    fetchMode 'levelOne', FetchMode.JOIN
    fetchMode 'levelOne.levelTwo', FetchMode.JOIN
    fetchMode 'levelOne.levelTwo.levelThree', FetchMode.JOIN
}

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