51.数据访问-CRUD实验
数据访问-CRUD实验-数据列表展示
官方文档 - CRUD接口
使用MyBatis Plus提供的IService,ServiceImpl,减轻Service层开发工作。
import com.lun.hellomybatisplus.model.User;
import com.baomidou.mybatisplus.extension.service.IService;
import java.util.List;
/**
* Service 的CRUD也不用写了
*/
public interface UserService extends IService<User> {
//此处故意为空
}
import com.lun.hellomybatisplus.model.User;
import com.lun.hellomybatisplus.mapper.UserMapper;
import com.lun.hellomybatisplus.service.UserService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper,User> implements UserService {
//此处故意为空
}
与下一节联合在一起
数据访问-CRUD实验-分页数据展示
与下一节联合在一起
数据访问-CRUD实验-删除用户完成
添加分页插件:
@Configuration
public class MyBatisConfig {
/**
* MybatisPlusInterceptor
* @return
*/
@Bean
public MybatisPlusInterceptor paginationInterceptor() {
MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();
// 设置请求的页面大于最大页后操作, true调回到首页,false 继续请求 默认false
// paginationInterceptor.setOverflow(false);
// 设置最大单页限制数量,默认 500 条,-1 不受限制
// paginationInterceptor.setLimit(500);
// 开启 count 的 join 优化,只针对部分 left join
//这是分页拦截器
PaginationInnerInterceptor paginationInnerInterceptor = new PaginationInnerInterceptor();
paginationInnerInterceptor.setOverflow(true);
paginationInnerInterceptor.setMaxLimit(500L);
mybatisPlusInterceptor.addInnerInterceptor(paginationInnerInterceptor);
return mybatisPlusInterceptor;
}
}
<table class="display table table-bordered table-striped" id="dynamic-table">
<thead>
<tr>
<th>#</th>
<th>name</th>
<th>age</th>
<th>email</th>
<th>操作</th>
</tr>
</thead>
<tbody>
<tr class="gradeX" th:each="user: ${users.records}">
<td th:text="${user.id}"></td>
<td>[[${user.name}]]</td>
<td th:text="${user.age}">Win 95+</td>
<td th:text="${user.email}">4</td>
<td>
<a th:href="@{/user/delete/{id}(id=${user.id},pn=${users.current})}"
class="btn btn-danger btn-sm" type="button">删除</a>
</td>
</tr>
</tfoot>
</table>
<div class="row-fluid">
<div class="span6">
<div class="dataTables_info" id="dynamic-table_info">
当前第[[${users.current}]]页 总计 [[${users.pages}]]页 共[[${users.total}]]条记录
</div>
</div>
<div class="span6">
<div class="dataTables_paginate paging_bootstrap pagination">
<ul>
<li class="prev disabled"><a href="#">← 前一页</a></li>
<li th:class="${num == users.current?'active':''}"
th:each="num:${#numbers.sequence(1,users.pages)}" >
<a th:href="@{/dynamic_table(pn=${num})}">[[${num}]]</a>
</li>
<li class="next disabled"><a href="#">下一页 → </a></li>
</ul>
</div>
</div>
</div>
#numbers表示methods for formatting numeric objects.link
@GetMapping("/user/delete/{id}")
public String deleteUser(@PathVariable("id") Long id,
@RequestParam(value = "pn",defaultValue = "1")Integer pn,
RedirectAttributes ra){
userService.removeById(id);
ra.addAttribute("pn",pn);
return "redirect:/dynamic_table";
}
@GetMapping("/dynamic_table")
public String dynamic_table(@RequestParam(value="pn",defaultValue = "1") Integer pn,Model model){
//表格内容的遍历
//从数据库中查出user表中的用户进行展示
//构造分页参数
Page<User> page = new Page<>(pn, 2);
//调用page进行分页
Page<User> userPage = userService.page(page, null);
model.addAttribute("users",userPage);
return "table/dynamic_table";
}