SpringBoot---myBatis数据库操作

一，分页查询

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

@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

@Overridepublic 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

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

• 然后再resources下创建xml文件

•  <!--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>