ORMLite android class 字段是其他 class 的 id
ORMLite android class field is id of other class
如何使用 ORMLite 实现 2 classes 之间的关系?我知道外国字段,但我无法将非字符串部门字段添加到产品 class
Class 产品
@DatabaseTable(tableName = "PRODUCTS")
public class Product {
@DatabaseField(id = true)
private String id;
@DatabaseField()
private String name;
@DatabaseField() //This field is id of Department class
private String department;
部门class
@DatabaseTable(tableName = "DEPARTMENTS")
public class Department {
@DatabaseField(id = true)
private String id;
@DatabaseField()
private String name;
How to implement relationship between 2 classes using ORMLite? I know about foreign field, but i can't add non-string Department field to product class
RTFM 请。您是否看过任何文档或示例?这是 docs on foreign objects。您可以清楚地看到,您将 Department
放入 Product
而不是 String
。文档显示 Order
对象具有 Account
字段。
@DatabaseField
private Department department;
在幕后,ORMLite 所做的实际上只是将部门的 id
存储到您的 Product
中。如果您真的查看架构,那么您会在那里看到一个字符串,但您自己不会这样做。
然后当您检索 Product
时,它将有一个 Department
字段,但只会填写 id
。
代码中还有一个 foreign object example 可能也有帮助。
如何使用 ORMLite 实现 2 classes 之间的关系?我知道外国字段,但我无法将非字符串部门字段添加到产品 class
Class 产品
@DatabaseTable(tableName = "PRODUCTS")
public class Product {
@DatabaseField(id = true)
private String id;
@DatabaseField()
private String name;
@DatabaseField() //This field is id of Department class
private String department;
部门class
@DatabaseTable(tableName = "DEPARTMENTS")
public class Department {
@DatabaseField(id = true)
private String id;
@DatabaseField()
private String name;
How to implement relationship between 2 classes using ORMLite? I know about foreign field, but i can't add non-string Department field to product class
RTFM 请。您是否看过任何文档或示例?这是 docs on foreign objects。您可以清楚地看到,您将 Department
放入 Product
而不是 String
。文档显示 Order
对象具有 Account
字段。
@DatabaseField
private Department department;
在幕后,ORMLite 所做的实际上只是将部门的 id
存储到您的 Product
中。如果您真的查看架构,那么您会在那里看到一个字符串,但您自己不会这样做。
然后当您检索 Product
时,它将有一个 Department
字段,但只会填写 id
。
代码中还有一个 foreign object example 可能也有帮助。