SpringBoot---myBatis数据库操作

奋进的大马猴2023-11-03 13:30

一，分页查询

现在controller中设置参数，@RequestParam(defaultValue = "1") 设置默认值

java 复制代码

@GetMapping
public Result page(@RequestParam(defaultValue = "1") Integer page,
                 @RequestParam(defaultValue = "10") Integer pageSize,
                 String name, Short gender,
                 @DateTimeFormat(pattern = "yyyy-MM-dd") LocalDate begin,
                 @DateTimeFormat(pattern = "yyyy-MM-dd") LocalDate end){
log.info("分页查询, 参数: {},{},{},{},{},{}",page,pageSize,name,gender,begin,end);
//调用service分页查询
PageBean pageBean = empService.page(page,pageSize,name,gender,begin,end);
return Result.success(pageBean);
}

然后再service实现类中

java 复制代码

@Override
    public PageBean page(Integer page, Integer pageSize,String name, Short gender, LocalDate begin, LocalDate end) {
        //1. 设置分页参数
        PageHelper.startPage(page,pageSize);

        //2. 执行查询
        List<Emp> empList = empMapper.list(name, gender, begin, end);
        Page<Emp> p = (Page<Emp>) empList;

        //3. 封装PageBean对象
        PageBean pageBean = new PageBean(p.getTotal(), p.getResult());
        return pageBean;
    }

再Mapper接口中

java 复制代码

public List<Emp> list(String name, Short gender, LocalDate begin, LocalDate end);

然后再resources下创建xml文件

XML 复制代码

 <!--条件查询-->
    <select id="list" resultType="com.itheima.pojo.Emp">
        select *
        from emp
        <where>
          <if test="name != null and name != ''">
              name like concat('%', #{name}, '%')
          </if>
          <if test="gender != null">
              and gender = #{gender}
          </if>
          <if test="begin != null and end != null">
              and entrydate between #{begin} and #{end}
          </if>
        </where>
        order by update_time desc
    </select>