springboot项目中信息分页查询的常规操作流程

1、分页查询的执行过程

在实际的项目开发过程中,分页显示是很常见的页面布局；下面我们来梳理一下常规操作中分页查询的执行过程：

• 1. 页面发送ajax请求，将分页查询参数（page、pagesize、name等额外信息）提交到服务端
• 2. 服务端（controller）接收页面提交的数据并调用Service查询数据
• 3. Service调用Mapper操作数据库，查询分页数据
• 4. Controller将查询到的分页数据响应给页面
• 5. 页面接收到分页数据并通过前端组件（例如：ElementUI的Table组件）展示到页面上

2、页面发送ajax请求：

          async init () {
            const params = {
              page: this.page,
              pageSize: this.pageSize,
              name: this.input ? this.input : undefined
            }
            await getMemberList(params).then(res => {
              if (String(res.code) === '1') {
                this.tableData = res.data.records || []
                this.counts = res.data.total
              }
            }).catch(err => {
              this.$message.error('请求出错了：' + err)
            })
          },

3、创建mybaitisPlus的配置类

首先创建一个mybaitisPlus的配置类，使用mplus提供的分页插件进行过滤查询

package com.tigerhhzz.wuaimai.config;

import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * 配置MP的分页插件
 */
@Configuration
public class MybatisPlusConfig {

    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor(){
        MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();
        mybatisPlusInterceptor.addInnerInterceptor(new PaginationInnerInterceptor());
        return mybatisPlusInterceptor;
    }
}

3、写controller接口

然后在controller中写一个接口

    /**
     * 员工信息分页查询
     * @param page
     * @param pageSize
     * @param name
     * @return
     */
    @GetMapping("/page")
    public R<Page> page(int page, int pageSize, String name){
        log.info("page = {},pageSize = {},name = {}" ,page,pageSize,name);

        //构造分页构造器
        Page pageInfo = new Page(page,pageSize);

        //构造条件构造器
        LambdaQueryWrapper<Employee> queryWrapper = new LambdaQueryWrapper();
        //添加过滤条件
        queryWrapper.like(StringUtils.isNotEmpty(name),Employee::getName,name);
        //添加排序条件
        queryWrapper.orderByDesc(Employee::getUpdateTime);

        //执行查询
        employeeService.page(pageInfo,queryWrapper);

        return R.success(pageInfo);
    }

4、测试

响应给页面数据：

{
    "code":1,
    "msg":null,
    "data":{
        "records":[
            {
                "id":1634812678390161409,
                "username":"123456",
                "name":"zhangsan",
                "password":"xxxxxxx",
                "phone":"13133333333",
                "sex":"1",
                "idNumber":"130111119801018111",
                "status":1,
                "createTime":[
                    2023,
                    3,
                    12,
                    15,
                    4,
                    51
                ],
                "updateTime":[
                    2023,
                    3,
                    12,
                    15,
                    4,
                    51
                ],
                "createUser":1,
                "updateUser":1
            },
            {
                "id":1,
                "username":"admin",
                "name":"管理员",
                "password":"xxxxxx",
                "phone":"13812312312",
                "sex":"1",
                "idNumber":"110101199001010047",
                "status":1,
                "createTime":[
                    2021,
                    5,
                    6,
                    17,
                    20,
                    7
                ],
                "updateTime":[
                    2021,
                    5,
                    10,
                    2,
                    24,
                    9
                ],
                "createUser":1,
                "updateUser":1
            }
        ],
        "total":2,
        "size":10,
        "current":1,
        "orders":[

        ],
        "optimizeCountSql":true,
        "hitCount":false,
        "countId":null,
        "maxLimit":null,
        "searchCount":true,
        "pages":1
    },
    "map":{

    }
}