3 个实体之间的域关联

Question

我正在开发 Grails 应用程序。我创建了 3 个实体客户、产品和订单。一个客户可以有很多订单，但每个订单只能包含一个产品。因此，单个订单可以关联到 1 个客户和 1 个产品。这是我的域名：

客户：

class Customer {
    String name;
    String address;
    Integer phoneNumber;
    Date dateCreated

    static hasMany = [orders:Order]
    static constraints = {
        name nullable: false
        address nullable: false
    }
}

订单：

class Order {
    Customer customer
    Product product
    Date orderDate

    static hasOne = [customer:Customer,product:Product]

    static constraints = {

    }
}

产品：

class Product {
    String name;
    String description;
    Date dateCreated

    static hasMany = [orders:Order]

    static constraints = {
    }
}

我使用 generate-all 生成了控制器和视图，当我运行应用程序时，我收到此错误：

| Running Grails application
| Error 2015-04-19 17:22:35,289 [localhost-startStop-1] ERROR hbm2ddl.SchemaUpdate  - Unsuccessful: create table order (id bigint not null auto_increment, version bigint not null, customer_id bigint not null, order_date datetime not null, product_id bigint not null, primary key (id)) ENGINE=InnoDB
| Error 2015-04-19 17:22:35,290 [localhost-startStop-1] ERROR hbm2ddl.SchemaUpdate  - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'order (id bigint not null auto_increment, version bigint not null, customer_id b' at line 1
| Error 2015-04-19 17:22:35,373 [localhost-startStop-1] ERROR hbm2ddl.SchemaUpdate  - Unsuccessful: alter table order add index FK651874E2B2D0780 (product_id), add constraint FK651874E2B2D0780 foreign key (product_id) references product (id)
| Error 2015-04-19 17:22:35,373 [localhost-startStop-1] ERROR hbm2ddl.SchemaUpdate  - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'order add index FK651874E2B2D0780 (product_id), add constraint FK651874E2B2D0780' at line 1
| Error 2015-04-19 17:22:35,373 [localhost-startStop-1] ERROR hbm2ddl.SchemaUpdate  - Unsuccessful: alter table order add index FK651874E89AD9194 (customer_id), add constraint FK651874E89AD9194 foreign key (customer_id) references customer (id)
| Error 2015-04-19 17:22:35,373 [localhost-startStop-1] ERROR hbm2ddl.SchemaUpdate  - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'order add index FK651874E89AD9194 (customer_id), add constraint FK651874E89AD919' at line 1

我也无法创建客户。域映射有什么问题吗？

我的数据源配置如下：

dataSource {
    driverClassName="com.mysql.jdbc.Driver"
    dialect="org.hibernate.dialect.MySQL5InnoDBDialect"
    url="jdbc:mysql://localhost:3306/aprilapp?useUnicode=true&characterEncoding=UTF-8"
    username="root"
    password="root"
    dbCreate = "update" // one of 'create', 'create-drop', 'update', 'validate', ''
}

Answer 1

您将 table 命名为 order，这是保留的 SQL 关键字。选择另一个 table 名称。

3 个实体之间的域关联

Domain association among 3 entities

grails

hibernate

grails-orm