全部分页查询获取计数根据用户名查询根据主键批量修改新增

全部分页查询

//sql select * from tb_user limit #{pageSize},#{pageNumber} //java PageHelper.startPage(pageSize,PageNumber); userMapper.selectByExample(null); @Service public class TbUserDubboServiceImpl implements TbUserDubboService{ @Autowired private UserMapper tbUserMapper; @Override public List<TbUser> selectAllUserByPage(int pageSize,int pageNumber){ //开启分页 PageHelper.startPage(pageSize,pageNumber); //全部查询查询 List<TbItem> list=tbUserMapper.selectByExample(null); //分页 PageInfo<TbItem> pageInfo=new PageInfo(list); return pageInfo.getList(); } }

获取计数

//sql select count(*) from tb_user //java userMapper.countByExample(null); @Service public class TbUserDubboServiceImpl implements TbUserDubboService{ @Autowired private UserMapper tbUserMapper; @Override public long selectCount(){ return tbUserMapper.countByExample(null); } }

根据用户名查询

//sql select * from tb_user where username=#{username} //java UserExample example=new UserExample(); example.create.Criteria().andUsernameEqualTo(username); userMapper.selectByExample(exmaple); @Service public class TbUserDubboServiceImpl implements TbUserDubboService{ @Autowired private UserMapper tbUserMapper; @Override public TbUser selectUserByUsername(String username){ //构建查询条件 UserExample userExample=new UserExample(); userExample.createCriteria().andUsernameEqualTo(username); //条件查询 List<User> list=tbUserMapper.selectByExample(userExample); //判断查询结果 if(null != list && list.size()>0){ return list.get(0); } return null; } }

根据主键批量修改

//sql update tb_user set status=#{status} where id=#{id} //java userMapper.updateByPrimaryKeySelective(tbUser); @Service public class TbUserDubboServiceImpl implements TbUserDubboService{ @Autowired private UserMapper tbUserMapper; @Override //声明式事务注解 - 监听异常，有异常则执行事务回滚 @Transactional public TbUser updateStatusByIds(long[] ids, int status) throws DaoException{ int index=0; //遍历ids for(long id : ids){ TbUser tbUser=new TbUser(); tbUser.setId(id); tbUser.setStatus((byte)status); tbUser.setUpdateTime(new Date()); //条件更新 //selective表示有值就操作，无值不操作 index +=tbUserMapper.updateByPrimaryKeySelective(tbUser); } //判断查询结果 if(index == ids.length){ return 1; } //如果操作失败，应该进行事务回滚 //return index; throw new DaoException("批量修改失败"); } }

新增

//sql insert into tb_user values(#{id},#{name}...) //java userMapper.insert(tbUser) @Service public class TbUserDubboServiceImpl implements TbUserDubboService{ @Autowired private UserMapper tbUserMapper; @Override //声明式事务注解 - 监听异常，有异常则执行事务回滚 @Transactional public TbUser updateStatusByIds(TbUser tbUser) throws DaoException{ int index=tbUserMapper.insert(tbUser); //判断查询结果 if(index == 1){ return 1; } //如果操作失败，应该进行事务回滚 //return index; throw new DaoException("新增失败"); } }