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OneToOne OneToMany
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MAPPING.md
81
MAPPING.md
@ -52,30 +52,15 @@ public class UserDO {
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* 一对一
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*/
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@TableField(exist = false)
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@MPJMapping(tag = UserDO.class, thisField = "pid" /*joinField = "id" 可以不填默认获取主键*/)
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@MPJMapping(tag = UserDO.class, thisField = "pid", joinField = "pid")
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private UserDO pUser;
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/**
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* 一对多
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*/
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@TableField(exist = false)
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@MPJMapping(tag = UserAddressDO.class, /*thisField = "id" 可以不填默认获取主键*/ joinField = "userId")
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private List<UserAddressDO> addressDOList;
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}
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```
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UserAddressDO.java
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```java
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@Data
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@TableName("user_address")
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public class UserAddressDO {
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@TableId
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private Integer id;
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private Integer userId;
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/* 其他属性略 */
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@MPJMapping(tag = UserAddressDO.class, thisField = "id", joinField = "userId")
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private List<UserDO> childUserList;
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}
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```
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@ -83,45 +68,61 @@ public class UserAddressDO {
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```java
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/**
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* 一对一,一对多关系映射查询
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* 映射只对MPJBaseDeepService中的方法有效果 ,一般以Deep结尾,比如 getByIdDeep listByIdsDeep 等
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* 如果不需要关系映射就使用mybatis plus原生方法即可,比如 getById listByIds 等
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*
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* @see com.github.yulichang.base.MPJBaseDeepService
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*/
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@SpringBootTest
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public class MPJDeepTest {
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class MappingTest {
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@Resource
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private UserService userService;
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/**
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* 根据id查询
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* <p>
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* 查询过程:
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* 一共查询了3次
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* 第一次查询目标UserDO
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* 第二次根据pid查询上级用户
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* 第三次根据自身id查询下级用户
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*/
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@Test
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void test1() {
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UserDO deep = userService.getByIdDeep(1);
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UserDO deep = userService.getByIdDeep(2);
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System.out.println(deep);
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}
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/**
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* 查询全部
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* <p>
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* 查询过程:
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* 一共查询了3次
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* 第一次查询目标UserDO集合
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* 第二次根据pid查询上级用户(不会一条记录一条记录的去查询,对pid进行汇总,用in语句一次性查出来,然后进行匹配)
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* 第三次根据自身id查询下级用户(不会一条记录一条记录的去查询,对id进行汇总,用in语句一次性查出来,然后进行匹配)
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*/
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@Test
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void test2() {
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List<UserDO> list = userService.listByIdsDeep(Arrays.asList(1, 4));
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List<UserDO> list = userService.listDeep();
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list.forEach(System.out::println);
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}
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/**
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* 分页查询
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* <p>
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* 查询过程与上面一致
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*/
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@Test
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void test3() {
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List<UserDO> list = userService.listByMapDeep(new HashMap<String, Object>() {{
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put("id", 1);
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}});
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list.forEach(System.out::println);
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Page<UserDO> page = userService.pageDeep(new Page<>(2, 2));
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page.getRecords().forEach(System.out::println);
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}
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@Test
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void test4() {
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UserDO one = userService.getOneDeep(Wrappers.<UserDO>lambdaQuery()
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.eq(UserDO::getId, 1));
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System.out.println(one);
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}
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@Test
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void test5() {
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Map<String, Object> deep = userService.getMapDeep(Wrappers.<UserDO>lambdaQuery()
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.eq(UserDO::getId, 1));
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System.out.println(deep);
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}
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}
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```
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MPJMapping 说明:
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@ -130,7 +131,9 @@ MPJMapping 说明:
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* MPJMapping thisField 当前类关联对应的字段的属性名,可以不填,默认为当前类的主键
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* MPJMapping joinField 关联类对应的字段的属性名,可以不填,默认为关联类的主键
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* MPJMapping isThrowExp 一对一查询时,如果查询到多条记录是否抛出异常,true:抛出异常,false:获取列表第一条数据
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* 更多功能请看代码注释 [MPJMapping](https://gitee.com/best_handsome/mybatis-plus-join/blob/master/src/main/java/com/github/yulichang/annotation/MPJMapping.java)
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*
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更多功能请看代码注释 [MPJMapping](https://gitee.com/best_handsome/mybatis-plus-join/blob/master/src/main/java/com/github/yulichang/annotation/MPJMapping.java)
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