使用@Fetch加载数据时如何添加动态where代码？

Question

我使用mybatis-mp框架进行开发，框架的url是[这里](https://github.com/mybatis-mp)。

框架版本：1.5.8

VO课程

@Data
@ResultEntity(SysUser.class)
public class SysUserVo {

    private Integer id;

    private String userName;

    private Integer roleId
    
 
    @ResultEntityField(property = "password")
    private String pwd;
    
    @Fetch(source = SysUser.class, property = "roleId", target = SysRole.class, targetProperty = "id")
    private SysRoleVo sysRole;
    
}

查询码

List<SysUserRoleVO> list = QueryChain.of(sysUserMapper)
        .like(SysUser::getUser,"ad") 
        .returnType(SysUserRoleVO.class)
        .list();

我想在 SysRole.type = 1 时加载 SysRole，我该怎么办？

Answer 1

您可以使用自定义查询或修改“@Fetch”注释逻辑。 “mybatis-plus”不直接支持注释中的条件获取，因此您需要在查询逻辑中处理这个问题。我假设您有 SysRole 的映射器。如果是这样，请获取“type = 1”的所有角色，然后在“SysUserVo”对象中手动设置“SysRole”字段。它应该看起来像这样：

@Mapper
public interface SysRoleMapper {
    @Select("SELECT * FROM sys_role WHERE type = 1")
    List<SysRole> selectActiveRoles();
}

List<SysUserVo> list = QueryChain.of(sysUserMapper)
        .like(SysUser::getUser, "ad")
        .select(SysUser::getId, SysUser::getUserName, SysUser::getRoleId) 
        .list();

List<SysRole> activeRoles = sysRoleMapper.selectActiveRoles();
Map<Integer, SysRole> roleMap = activeRoles.stream().collect(Collectors.toMap(SysRole::getId, Function.identity()));

list.forEach(user -> {
    SysRole role = roleMap.get(user.getRoleId());
    if (role != null) {
        user.setSysRole(new SysRoleVo(role));
    }
});