Question

当我遇到问题时，我正在处理一个简单的grails项目。我做了很多研究，但我找不到正确的答案。

事情是，我有3个域类，即库存，用户和运动，它们之间的关系是 one-to 广告资源和移动的 用户和移动相同运动几乎处于中间位置。我设法很好地连接了库存和移动，但是其他关系在下面显示了错误。

Error | Error loading plugin manager: Property [movements] in class [classcom.inventory.User] is a bidirectional one-to-many with two possible properties on the inverse side. Either name one of the properties on other side of the relationship [user] or use the 'mappedBy' static to define the property that the relationship is mapped with. Example: static mappedBy = [movements:'myprop'] (Use--stacktrace to see the full trace) | Error Forked Grails VM exited with error

这是我的域类：

用户：

class User { String userID String fullName String position Department department String toString(){ fullName } static hasMany = [inventories: Inventory, movements: Movement] static constraints = { userID blank: false, unique: true fullName blank: false position() department() movements nullable: true } }

机芯：

class Movement { User oldUser User newUser Inventory inventoryID Date movementDate User userResponsible //static belongsTo = User static constraints = { inventoryID blank: false oldUser blank: false newUser blank: false movementDate() userResponsible blank: false } }

清单：

class Inventory { String inventoryID String code String description String serial_num Date purchase_date byte[] image Date record_date String remarks Type type Brand brand User user static hasMany = [movements: Movement] String toString(){ "$inventoryID, $type" } static constraints = { inventoryID blank: false, unique: true code blank: false description nullable: true, maxSize: 1000 serial_num blank: false purchase_date() image nullable: true, maxSize: 1000000 record_date() remarks nullable: true, maxSize: 1000 type() brand() user() } }

任何想法如何解决错误.. ??

Answer 1

这里的问题是gorm无法区分Movements类上的newUser和oldUser。尝试添加mappedBy部分并将另一部分添加到您的用户类的hasMany属性中，下面是一个应该有效的示例：

    class User {

    String userID
    String fullName
    String position
    Department department 

    String toString(){
        fullName
    }

    static hasMany = [inventories: Inventory, movementsByOldUser: Movement, movementsByNewUser: Movement]
    static mappedBy = [movementsByOldUser: 'oldUser', movementsByNewUser: 'newUser']
    static constraints = {
        userID blank: false, unique: true
        fullName blank: false
        position()
        department()
        movements nullable: true
    }
}

有关文档参考，请参阅：http://www.grails.org/doc/2.2.x/ref/Domain%20Classes/mappedBy.html

在Grails / Groovy中加载插件管理器时出错

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