第二十章第六节：引入mybatis分页插件

1、解决查询列表上总数为0条的问题

需要引入mybatis plus分页插件
参考：https://mybatis.plus/guide/page.html

1、创建mybatis分页配置类

com.applesnt.onlinemall.product.config.MybatisConfig

package com.applesnt.onlinemall.product.config;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration//配置类
@EnableTransactionManagement //开启事务
@MapperScan("com.applesnt.onlinemall.product.dao") //扫描包
public class MybatisConfig {
    
}

2、引入mybatis分页插件

package com.applesnt.onlinemall.product.config;

import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import com.baomidou.mybatisplus.extension.plugins.pagination.optimize.JsqlParserCountOptimize;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration//配置类
@EnableTransactionManagement //开启事务
@MapperScan("com.applesnt.onlinemall.product.dao")//扫描包
public class MybatisConfig {
    //引入mybatis分页插件
    //参考：https://mybatis.plus/guide/page.html
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        // 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(true);
        // 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
        paginationInterceptor.setCountSqlParser(new JsqlParserCountOptimize(true));
        return paginationInterceptor;
    }

}

3、重启相关服务 查看效果