我有两个域类.一个是"合作伙伴",另一个是"客户".客户可以是合作伙伴的一部分,合作伙伴可以拥有一个或多个客户:
class Customer {
Integer id
String name
static hasOne = [partner:Partner]
static mapping = {
partner joinTable:[name:'PartnerMap',column:'partner_id',key:'customer_id']
}
}
class Partner {
Integer id
static hasMany = [customers:Customer]
static mapping = {
customers joinTable:[name:'PartnerMap',column:'customer_id',key:'partner_id']
}
}
但是,每当我试图查看客户是否是合作伙伴的一部分时,就像这样:
def customers = Customer.list()
customers.each {
if (it.partner) {
println "Partner!"
}
}
我收到以下错误:
org.springframework.dao.InvalidDataAccessResourceUsageException: could not execute query; SQL [select this_.customer_id as customer1_162_0_, this_.company as company162_0_, this_.display_name as display3_162_0_, this_.parent_customer_id as parent4_162_0_, this_.partner_id as partner5_162_0_, this_.server_id as server6_162_0_, this_.status as status162_0_, …任何人都可以告诉我什么是实现软删除的好方法？我可以deleted在班上找到一个属性,但我的问题是如何轻松忽略deleted = true我的搜索,列表等中的实例.
所以,而不是说Domain.findByDeleted(true)只是Domain.list()忽略已删除的实例,而不是说Domain.findByPropertyAndDeleted('property', true)只是说Domain.findByProperty('property').
有这么好的方法吗？
假设我有以下层次的域类.
class School {
String name
static hasMany = [teachers: Teacher, students: Student]
}
class Teacher {
String name
static belongsTo = [school: School]
static hasMany = [students: Student]
}
class Student {
String name
static belongsTo = [school: School, teacher: Teacher]
}
我尝试了两种不同的方法来拯救学校,老师和学生.
尝试1:
def school = new School(name: "School").save()
def teacher = new Teacher(name: "Teacher", school: school).save()
def student = new Student(name: "Student", school: school, teacher: teacher).save(flush: true)
它看起来保存得当但是我跑的时候:
println(school.students*.name)
它打印null.
所以我决定尝试不同的方法.
尝试2:
def school = …我试图更新我的测试,因为我对我的服务类进行了更改.在我添加的服务方法中("withNewSession")
Domain.withNewSession {
.. ...
domain.save()
}
因为我正在使用"withNewSession",所以我得到方法缺少异常,因为这个域在我的测试类中被模拟.
我有两个表,其中一个(遗留表:A)有两个字段应该作为复合外键,另一个(新表:B)应该使用复合主键作为each row:A has one row:B关系.如何根据GORM描述这些表格？
到目前为止,我已经能够创建一个反映旧表的域类:A
class A {
...
//composite foreign key to link B class
String className;
String eventName;
B b; //instance of B to be related
static mapping = {
table 'a_table';
id column: 'id';
className column: 'class_name';
eventName column: 'event_name';
//b: ???
}
}
哪个有效,但我无法创造new class:B和关系.
我试图将B声明为:
class B implements Serializable{
static auditable = true;
String name;
String className;
String eventName;
static mapping = {
//supposed to make a composite PK
id …在我的grails应用程序中,我正在从中提取文本params并将其用作我的域查询中的参数:
例:
def color = Colors.findByName(params.colorname)
我想有人可以摆弄params.colorname参数来对我的mysql数据库运行错误的查询.
有哪些好的做法可以防止这些事情发生？
ORM如何工作的新功能所以请耐心等待.我有一个域类
class MyClass()
{
String myName
Date mydate
}
我用相同的字符串和不同的日期引导了几个例子.然后在我的gsp中,我对控制器方法执行ajax调用
def MyAjaxCall
{
def classes = MyClass.findAll()
}
我怎样才能改变这一点,所以我只返回myName最新的mydate？谢谢
如何on delete cascade使用外键GORM映射在数据库级别实现？
我不是指应用程序级别的级联删除(由GORM完成的顺序删除).
使用MongoDB/GORM/Groovy on Java 1.7.0_55,gradle 1.11和spring-boot-gradle-plugin:1.2.1.RELEASE.获取此springboot项目的启动问题.
我正在按原样运行项目,但application.yml我的远程mongodb 的以下更改除外:
spring:
mongodb:
host: "10.160.8.1"
databaseName: "citydb"
**在启动时,我看到这个bean初始化错误 mappingMongoConverter
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mongoTemplate' defined in class path resource [org/springframework/boot/autoconfigure/mongo/MongoDataAutoConfiguration.class]:
Unsatisfied dependency expressed through constructor argument with index 1 of type [org.springframework.data.mongodb.core.convert.MongoConverter]: : Error creating bean with name 'mappingMongoConverter' defined in class path resource [org/springframework/boot/autoconfigure/mongo/MongoDataAutoConfiguration.class]:
Unsatisfied dependency expressed through constructor argument with index 1 of type [org.springframework.data.mongodb.core.mapping.MongoMappingContext]: : …我正在尝试更改Visitor表中用于Userid 的外键列名.该列现在命名user_id,我想将其更改为who_id.
最小User域类:
class User {
static hasMany = [
visitor: Visitor
]
String uid
...
}
最小Visitor域类:
class Visitor {
static belongsTo = [user: User]
....
}
我试过mappedBy但没有成功,是否有另一种方法可以使用属性User作为外键Visitor？