feat: 支持更新指定字段

mapper/src/main/java/io/mybatis/mapper/BaseMapper.java

@@ -62,6 +62,17 @@ default ExampleWrapper<T, I> wrapper() {
   @UpdateProvider(type = FnProvider.class, method = "updateByPrimaryKeySelectiveWithForceFields")
   <S extends T> int updateByPrimaryKeySelectiveWithForceFields(@Param("entity") S entity, @Param("fns") Fn.Fns<T> forceUpdateFields);
 
+  /**
+   * 根据主键更新指定的字段
+   *
+   * @param entity       实体类型
+   * @param updateFields 指定更新的字段
+   * @return 1成功，0失败
+   */
+  @Lang(Caching.class)
+  @UpdateProvider(type = FnProvider.class, method = "updateForFieldListByPrimaryKey")
+  <S extends T> int updateForFieldListByPrimaryKey(@Param("entity") S entity, @Param("fns") Fn.Fns<T> updateFields);
+
   /**
    * 根据指定字段集合查询：field in (fieldValueList)
    * <p>

mapper/src/main/java/io/mybatis/mapper/fn/FnProvider.java

@@ -52,6 +52,27 @@ public String getSql(EntityTable entity) {
     });
   }
 
+  /**
+   * 根据主键更新指定的字段
+   *
+   * @param providerContext 上下文
+   * @return cacheKey
+   */
+  public static String updateForFieldListByPrimaryKey(ProviderContext providerContext) {
+    return SqlScript.caching(providerContext, new SqlScript() {
+      @Override
+      public String getSql(EntityTable entity) {
+        return "UPDATE " + entity.tableName()
+            + set(() ->
+            entity.updateColumns().stream().map(column ->
+                choose(() ->
+                    whenTest("fns != null and fns.fieldNames().contains('" + column.property() + "')", () -> column.columnEqualsProperty("entity.") + ","))
+            ).collect(Collectors.joining(LF)))
+            + where(() -> entity.idColumns().stream().map(column -> column.columnEqualsProperty("entity.")).collect(Collectors.joining(" AND ")));
+      }
+    });
+  }
+
   /**
    * 根据实体字段条件查询唯一的实体，根据实体字段条件批量查询，查询结果的数量由方法定义
    *

mapper/src/test/java/io/mybatis/mapper/fn/UserFnMapperTest.java

@@ -46,6 +46,31 @@ public void testUpdateByPrimaryKeySelectiveWithForceFields() {
     }
   }
 
+  @Test
+  public void testUpdateForFieldListByPrimaryKey() {
+    SqlSession sqlSession = getSqlSession();
+    try {
+      // 元数据（1, '张无忌', '男', 1)
+      UserMapper mapper = sqlSession.getMapper(UserMapper.class);
+      User user = mapper.selectByPrimaryKey(1L).get();
+      user.setUserName("test");
+      user.setSex("女");
+      user.setStatus(false);
+      int count = mapper.updateForFieldListByPrimaryKey(user, Fn.of(User::getUserName, User::getStatus));
+      Assert.assertEquals(1, count);
+      user = mapper.selectByPrimaryKey(1L).get();
+      // 断言 sex 不会被更新
+      Assert.assertEquals("男", user.getSex());
+      // 断言userName被成功更新
+      Assert.assertEquals("test", user.getUserName());
+      // 短信 status不会被更新，user status 为不允许更新字段, 所以这里不会更新
+      Assert.assertEquals(user.getStatus(), true);
+    } finally {
+      //不要忘记关闭sqlSession
+      sqlSession.close();
+    }
+  }
+
   @Test
   public void testSelectColumnsOne() {
     SqlSession sqlSession = getSqlSession();

service/src/main/java/io/mybatis/service/AbstractService.java

@@ -84,6 +84,13 @@ public T update(T entity) {
     return entity;
   }
 
+  @Override
+  public T update(T entity, Fn<T, Object>... updateFields) {
+    Assert.isTrue(baseMapper.updateForFieldListByPrimaryKey(
+        entity, Fn.of(updateFields)) == 1, UPDATE_FAILURE);
+    return entity;
+  }
+
   @Override
   public T updateSelective(T entity) {
     Assert.isTrue(baseMapper.updateByPrimaryKeySelective(entity) == 1, UPDATE_FAILURE);

service/src/main/java/io/mybatis/service/EntityService.java

@@ -55,6 +55,15 @@ public interface EntityService<T, I extends Serializable> {
    */
   T update(T entity);
 
+  /**
+   * 更新（指定字段）
+   *
+   * @param entity       实体类
+   * @param updateFields 需要更新的字段
+   * @return 返回更新成功后的实体，远程服务调用时，由于序列化和反序列化，入参和返回值不是同一个对象
+   */
+  T update(T entity, Fn<T, Object>... updateFields);
+
   /**
    * 更新（非空字段）
    *

service/src/test/java/io/mybatis/service/ServiceTest.java

@@ -182,6 +182,28 @@ public void testUserService() {
     Assert.assertTrue(userService.findOne(user) != null);
   }
 
+  @Test
+  public void testUpdate() {
+    // 元数据 (1, 'admin', 1)
+    UserService userService = context.getBean(UserService.class);
+    User user = userService.findById(1);
+    Assert.assertNotNull(user);
+
+    user.setName("administrator");
+    user.setRoleId(11);
+    userService.update(user, User::getName);
+    user = userService.findById(1);
+    Assert.assertEquals("administrator", user.getName());
+    Assert.assertEquals(1, (int) user.getRoleId());
+
+    user.setName("admin");
+    user.setRoleId(11);
+    userService.update(user, User::getRoleId);
+    user = userService.findById(1);
+    Assert.assertEquals("administrator", user.getName());
+    Assert.assertEquals(11, (int) user.getRoleId());
+  }
+
   @Test
   public void testIssues50() {
     UserService userService = context.getBean(UserService.class);