删除父行中的grails外键错误

Question

我有以下情况：

class Receipt {

   BigDecimal totalAmount;
   Date releaseDate;

   @NotNull
   Integer vatPercentage;

   @NotNull
   Integer discount;

   Boolean isPayed;
   Boolean isInvoice;
   Boolean hasStampDuty;

   Integer documentNumber;

   @NotNull
   static belongsTo = [patient:Patient, doctor:Doctor]

   @NotNull
   static hasMany = [healthServices:Receipt_HealthService]


    static constraints = {
        healthServices(blank:  false)
        patient(blank: false)
        totalAmount(blank: false, )
        vatPercentage(blank: false, nullable: false)

    }


}


class HealthService {

   int vat;
   String description;
   BigDecimal price;

   static belongsTo = [healthServiceType:HealthServiceType, doctor:Doctor]

   static constraints = {
      healthServiceType(blank: false)
      vat(size: 11..11)
      description(maxSize: 255)

    }
}  


class Receipt_HealthService {

   Receipt receipt
   HealthService healthService
   int quantity = 1

   static constraints = {
   }
}

我手动创建了 Receipt_HealthService 域 class，如 post 中所述。一切正常，但是当我尝试删除 Receipt 实例时，我看到以下错误：

Cannot delete or update a parent row: a foreign key constraint fails
(`my_localdb`.`receipt_health_service`, CONSTRAINT 
`FK96DE98B9D3292D2C` FOREIGN KEY (`receipt_id`) REFERENCES `receipt`(`id`))

为什么会这样？为什么 Receipt_HealthService 个实例没有自动删除？我需要更改什么才能允许自动删除并消除错误？

Answer 1

class Receipt_HealthService 没有 belongsTo，因此 Receipt 的删除没有级联。参见 http://grails.github.io/grails-doc/latest/guide/GORM.html#cascades。

您可以按以下方式更改 Receipt_HealthService：

class Receipt_HealthService {
   ...
   static belongsTo = [receipt: Receipt]
}

或者尝试明确定义级联行为（参见 http://grails.github.io/grails-doc/latest/guide/GORM.html#customCascadeBehaviour）。

另一种可能性是将 beforeDelete 添加到 Receipt 以负责删除 healthServices 中的每个条目。参见 http://grails.github.io/grails-doc/latest/guide/GORM.html#eventsAutoTimestamping

对于最后一个选项，您可以检查 Spring Security Plugin 中的 classes User、UserRole 和 Role 作为示例。我没有在网上找到示例项目，但您可以在示例项目中安装插件，然后运行 grails s2-quickstart 看看 User#beforeDelete 的样子（参见 https://grails-plugins.github.io/grails-spring-security-core/ref/Scripts/s2-quickstart.html ).

删除父行中的grails外键错误

grails foreign key error in delete parent row

grails

foreign-key-relationship