1[代码解析004] MybatisPlus之QueryWrapper、LambdaQueryWrapper以及LambdaQueryChainWrapper用法

1、代码片段

  /**
     * 获取角色已分配菜单列表
     * @param xxxRoleId
     * @return RoleMenuList
     */
    @ApiOperation(value = "获取角色已分配菜单列表")
    @GetMapping(value = "/getRoleMenuList/{aaaRoleId}")
    public AjaxResult getRoleMenuList(@PathVariable("aaaRoleId") String aaaRoleId){
        //根据角色id查询角色菜单关联表查出所有角色菜单关联列表
        LambdaQueryWrapper<AaaRoleMenu> aaaMenuEntityWrapper = new LambdaQueryWrapper<>();
        aaaMenuEntityWrapper.eq(AaaRoleMenu::getDelFlag,NumberUtil.ZERO_STR);
        aaaMenuEntityWrapper.eq(AaaRoleMenu::getRoleId, aaaRoleId);
        List<SaaaRoleMenu> aaaRoleMenuList = aaaRoleMenuService.list(aaaMenuEntityWrapper);
        //根据角色菜单关联表中的菜单id查询出菜单列表
        Set<String> menuIdList = new HashSet<>();
        if (!CollectionUtils.isEmpty(aaaRoleMenuList)){
            menuIdList = aaaRoleMenuList.stream().collect(Collectors.groupingBy(SaaaRoleMenu::getMenuId)).keySet();
        }
        List<SaaaMenu> aaaMenuList = Lists.newArrayList();
        if (!CollectionUtils.isEmpty(menuIdList)){
            LambdaQueryWrapper<SaaaMenu> aaaMenuWrapper= new LambdaQueryWrapper<>();
            aaaMenuWrapper.eq(SaaaMenu::getDelFlag,NumberUtil.ZERO_STR);
            aaaMenuList = aaaMenuService.listByIds(menuIdList); //批量查询
        }
        return AjaxResult.success(aaaMenuList);
    }

2、涉及源码

4、涉及知识点

参考文章：http://t.zoukankan.com/donleo123-p-14109889.html

mybatis plus 条件构造器queryWrapper学习