springboot2 pagehelper 使用笔记

作者：o_cYj
博客专栏：
https://blog.csdn.net/o_cYj

pom.xml

<parent>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-parentartifactId>
    <version>2.0.4.RELEASEversion>
    <relativePath/> 
parent>

<dependency>
    <groupId>com.github.pagehelpergroupId>
    <artifactId>pagehelper-spring-boot-starterartifactId>
    <version>1.2.5version>
dependency>

引入的jar包必须是要pagehelper-spring-boot-starter如果单独引入pagehelper的话，分页会不成功，现在导入的结果如下：

使用时PageHelper.startPage(pageNum, pageSize)一定要放在列表查询上面，这样在查询时会查出相应的数据量且会查询出总数，像图中总数量有两条，page里面查询出来了是2，但list只查出了1条，因为我传的分页是pageNo=1,pageSize=1

PageHelper.startPage(pageNum, pageSize);
List systemUserList = systemUserMapper.page(find);
PageInfo page = new PageInfo<>(systemUserList);

打印的sql如下所示

Preparing: SELECT count(0) FROM (SELECT su.id, su.name, su.nick_name, su.email, su.phone, su.sex, su.fail_num, su.status, su.create_time, su.update_time, GROUP_CONCAT(sr.name) AS rolesName FROM SYSTEM_USER su, system_user_role sur, system_role sr WHERE su.id = sur.user_id AND sur.role_id = sr.id GROUP BY su.id) table_count 
Parameters: 
Total: 1
Preparing: SELECT su.id, su.name, su.nick_name, su.email, su.phone, su.sex, su.fail_num, su.status, su.create_time, su.update_time, group_concat(sr.name) as rolesName FROM SYSTEM_USER su, system_user_role sur, system_role sr WHERE su.id = sur.user_id AND sur.role_id = sr.id GROUP BY su.id LIMIT ? 
Parameters: 1(Integer)
Total: 1